What's the weak link in my 440 build?

Its been quite a while since I’ve made a post on here as I’ve been stationed in In Japan for the last three and a half years and my Duster has been in government storage. Anyways, I should be back in the states in the next few months and back to working on my car. I’m by no means an engine builder so I’d like to get some opinions on my current build and where improvements can be made to get some more power. I’d really love to get into the low 10’s. The car probably weighs around 3300 lbs and according to the online calculators I’ll need around 650hp.

Current set-up
440 with stock forged crank and reconditioned LY rods, Icon forged pistons, and unmodified stealth heads giving me 10.23:1 compression and .039 quench. Edelbrock RPM intake, Atomic EFI (rated to 620HP), and 2” fenderwell headers to 3.5” collector. MSD Digital 6AL and all MSD ignition components. Currently running a Comp solid roller cam with 110 LSA, 243* duration at .050, .550 lift but using 1.6 rockers so actual lift is around .587 and slightly more duration. 4 speed, 3.55 rear gear, and 26x11 M/T street radials. I’m not sure what kind of power I’m currently making and I’ve never had it to the track with this engine. Runs on 91 octane. With my current cam and heads my calculated dynamic compression is 7.77:1 and 156 cranking PSI.

Future plans
If the Atomic EFI system can’t keep up I’ll switch back to an 850 CFM Holley carb.

I’ve got some weight reduction plans.

I’m thinking about ordering the Trickflow 240 CNC ported heads and switching to a single plane Victor intake. I’m sure this will increase power but I’m concerned it will move my powerband up beyond 6500 RPM above where I’m comfortable spinning it with LY rods. I want to keep the engine somewhat streetable. The head change would give me 10.82 static compression. Calculated Dynamic compression would be 8.2:1 and 168 cranking PSI.

I’ve considered ordering a more aggressive cam but again, I don’t want to have to rev above 6500 in order to take advantage of it.

Is there anything I’m not considering? Is 650 hp even a reasonable goal on 91 octane? Where is my money best spent?

sbh126 said:

Its been quite a while since I’ve made a post on here as I’ve been stationed in In Japan for the last three and a half years and my Duster has been in government storage. Anyways, I should be back in the states in the next few months and back to working on my car. I’m by no means an engine builder so I’d like to get some opinions on my current build and where improvements can be made to get some more power. I’d really love to get into the low 10’s. The car probably weighs around 3300 lbs and according to the online calculators I’ll need around 650hp.

Current set-up
440 with stock forged crank and reconditioned LY rods, Icon forged pistons, and unmodified stealth heads giving me 10.23:1 compression and .039 quench. Edelbrock RPM intake, Atomic EFI (rated to 620HP), and 2” fenderwell headers to 3.5” collector. MSD Digital 6AL and all MSD ignition components. Currently running a Comp solid roller cam with 110 LSA, 243* duration at .050, .550 lift but using 1.6 rockers so actual lift is around .587 and slightly more duration. 4 speed, 3.55 rear gear, and 26x11 M/T street radials. I’m not sure what kind of power I’m currently making and I’ve never had it to the track with this engine. Runs on 91 octane. With my current cam and heads my calculated dynamic compression is 7.77:1 and 156 cranking PSI.

Future plans
If the Atomic EFI system can’t keep up I’ll switch back to an 850 CFM Holley carb.

I’ve got some weight reduction plans.

I’m thinking about ordering the Trickflow 240 CNC ported heads and switching to a single plane Victor intake. I’m sure this will increase power but I’m concerned it will move my powerband up beyond 6500 RPM above where I’m comfortable spinning it with LY rods. I want to keep the engine somewhat streetable. The head change would give me 10.82 static compression. Calculated Dynamic compression would be 8.2:1 and 168 cranking PSI.

I’ve considered ordering a more aggressive cam but again, I don’t want to have to rev above 6500 in order to take advantage of it.

Is there anything I’m not considering? Is 650 hp even a reasonable goal on 91 octane? Where is my money best spent?

Click to expand...

Efi may pick up a few ponies but it's more for reliability also Maybe take a look at trick flows dyno on there 440 they made 620 with a near same cam, there's was hydraulic & .600 lift.
It's probably going to be cheaper to find a couple hundred pounds to remove first. Then go run your set up. To me yours sounds like a mid to high 11's. I might ad if your looking to run pump gas & have fun, & basically smoke 99% of cars on the road your already there. With the bigger cam you'll run out of air with the head & intake.
1 of those change one, change all scenarios & you may need The added compression to run a bigger cam & everything be happy. If you have enough aluminum in your engine compartment & can stay cool you'd be fine @ 11.0:1 The rods if your serious about even 550 hp I personally would oust them for an h-beam. Hope this helps, but to make clear your car sounds like a good street strip set up already. Best money spent would be add some cubic inches that makes everything easier. 512-528-543 but no more on a stock block...thats all just my opinion & stuff in my head I've picked up along the way. Also going low 10s you've gotta have more stuff done to your car then an 11& up car I believe

Well I can tell you what made an on track 600fwhp in my mates 3150lb 440 Dart>
MCH Eddy heads, approx 325cfm@.600, 12.5:1CR, MP. .590 sft cam, 270@.050, 2" hdrs, a 950DP then a 1050 Dom, Victor intake, car was a 727 with a 5000stall, 4.56/31"tyres, SS/springs and good shocks, was well sorted and used to pick them up level, ran 1.39 60's with a best of 1.36 and 10 teens@131>132..trapped@6800. That had LY rods in it and it lasted around 9 runs once he started to trap@6800rpm and threw 1 out....1/2" internal pick-up.

I can see 600hp with that set up with the 240's and the rest of what you have but the 3.55's are a killer with your stick. Hard to say where to spend the money for another 3/10's as that hp in your 3450lb@the line weight? would get you 10.40's@only 6000 trap according to my calcs. Personally I would spend it on the chassis as in 4.10's/28's and try and pick up some 60/ET that way, that set up would have you trapping around 6500.

sbh126 said:

Its been quite a while since I’ve made a post on here as I’ve been stationed in In Japan for the last three and a half years and my Duster has been in government storage. Anyways, I should be back in the states in the next few months and back to working on my car. I’m by no means an engine builder so I’d like to get some opinions on my current build and where improvements can be made to get some more power. I’d really love to get into the low 10’s. The car probably weighs around 3300 lbs and according to the online calculators I’ll need around 650hp.

Current set-up
440 with stock forged crank and reconditioned LY rods, Icon forged pistons, and unmodified stealth heads giving me 10.23:1 compression and .039 quench. Edelbrock RPM intake, Atomic EFI (rated to 620HP), and 2” fenderwell headers to 3.5” collector. MSD Digital 6AL and all MSD ignition components. Currently running a Comp solid roller cam with 110 LSA, 243* duration at .050, .550 lift but using 1.6 rockers so actual lift is around .587 and slightly more duration. 4 speed, 3.55 rear gear, and 26x11 M/T street radials. I’m not sure what kind of power I’m currently making and I’ve never had it to the track with this engine. Runs on 91 octane. With my current cam and heads my calculated dynamic compression is 7.77:1 and 156 cranking PSI.

Future plans
If the Atomic EFI system can’t keep up I’ll switch back to an 850 CFM Holley carb.

I’ve got some weight reduction plans.

I’m thinking about ordering the Trickflow 240 CNC ported heads and switching to a single plane Victor intake. I’m sure this will increase power but I’m concerned it will move my powerband up beyond 6500 RPM above where I’m comfortable spinning it with LY rods. I want to keep the engine somewhat streetable. The head change would give me 10.82 static compression. Calculated Dynamic compression would be 8.2:1 and 168 cranking PSI.

I’ve considered ordering a more aggressive cam but again, I don’t want to have to rev above 6500 in order to take advantage of it.

Is there anything I’m not considering? Is 650 hp even a reasonable goal on 91 octane? Where is my money best spent?

Click to expand...

also thank you for your service

sbh126 said:

Where is my money best spent?

Click to expand...

Traction aids or cheap back tires.

MOPARMAGA said:

Efi may pick up a few ponies but it's more for reliability also Maybe take a look at trick flows dyno on there 440 they made 620 with a near same cam, there's was hydraulic & .600 lift.
It's probably going to be cheaper to find a couple hundred pounds to remove first. Then go run your set up. To me yours sounds like a mid to high 11's. I might ad if your looking to run pump gas & have fun, & basically smoke 99% of cars on the road your already there. With the bigger cam you'll run out of air with the head & intake.
1 of those change one, change all scenarios & you may need The added compression to run a bigger cam & everything be happy. If you have enough aluminum in your engine compartment & can stay cool you'd be fine @ 11.0:1 The rods if your serious about even 550 hp I personally would oust them for an h-beam. Hope this helps, but to make clear your car sounds like a good street strip set up already. Best money spent would be add some cubic inches that makes everything easier. 512-528-543 but no more on a stock block...thats all just my opinion & stuff in my head I've picked up along the way. Also going low 10s you've gotta have more stuff done to your car then an 11& up car I believe

Click to expand...

I just tried to look this up and found a Hotrod article where they tried to repeat Trickflows test and ended up with 560hp. They were using a single plain intake and like you said the cam was very similar to mine and they had peak power at 5800. So I guess I don't need to worry too much about the power band moving out of reach. Also, the article didn't mention anything about porting so the CNC ported heads I'm looking at might make a bit more power.

I'll have to take a look at the available stroker kits. If I'm looking at buying rods and paying for a re-balance anyway it might be worth my time to go ahead and replace the whole rotating assembly. I appreciate the insight.

Hot Metal said:

Well I can tell you what made an on track 600fwhp in my mates 3150lb 440 Dart>
MCH Eddy heads, approx 325cfm@.600, 12.5:1CR, MP. .590 sft cam, 270@.050, 2" hdrs, a 950DP then a 1050 Dom, Victor intake, car was a 727 with a 5000stall, 4.56/31"tyres, SS/springs and good shocks, was well sorted and used to pick them up level, ran 1.39 60's with a best of 1.36 and 10 teens@131>132..trapped@6800. That had LY rods in it and it lasted around 9 runs once he started to trap@6800rpm and threw 1 out....1/2" internal pick-up.

I can see 600hp with that set up with the 240's and the rest of what you have but the 3.55's are a killer with your stick. Hard to say where to spend the money for another 3/10's as that hp in your 3450lb@the line weight? would get you 10.40's@only 6000 trap according to my calcs. Personally I would spend it on the chassis as in 4.10's/28's and try and pick up some 60/ET that way, that set up would have you trapping around 6500.

Click to expand...

I've been looking at some 29.5 street radials and either a 4.10 or 4.30 gear. I'll need to measure everything and make sure those tires will fit without too much work. I'm planning on moving the axle back a half inch or so. Hopefully that's enough. Also looking at Caltrac bars.

sbh126 said:

I've been looking at some 29.5 street radials and either a 4.10 or 4.30 gear. I'll need to measure everything and make sure those tires will fit without too much work. I'm planning on moving the axle back a half inch or so. Hopefully that's enough. Also looking at Caltrac bars.

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My mate mini tubbed the rear and also moved the Dana back 1" and this was a race only car. Going stroker is probably the only way your going to go 10 teens in that weight and keep it a street/strip car? which is what its going to be I think as you keep mentioning street radials. If your planning on using those tyres with a stick car that is a lethal combination for the street and will be a nightmare to get to hook@the track in my opinion made even worse with the extra torque of a stroker and if it hooks the rear won't last long if its an 8.3/4". You can drive it off the line and then hammer it but you'll lose ET defeating the whole $$ invested to get it in the teens. There are things like clutch tamers that would help but I would definitely put a pair of bias 10.5x28>29's slicks on the car@the track depending on gearing chosen and hope the rear lasts a while or go for a Dana.......You could of course keep it as it is now as a 440 which should be around the 540hp mark with the Stealths etc. without spending a whole load of $$$$ and put a small 125>150 N20 shot on it and achieve your goal that way leaving it on pump gas for the street.

Hello and Thanks for your service. There is a member not sure if on here but know he posts on moparts using prosport that just sold a duster that had a 500 ci stroker that ran in the mid 10's and very streetable maybe search see if you can find his posts

For street duty, I think I would ditch the 4speed for that combo.
Or tame the build and add NOS at the track.

The problem with a 4-gear and a big cam,
is trying to drive slow; 950rpm with 4.10s and 29s is ~7.5 mph. 800 is 6.3mph. And there is a very good chance that this will produce some serious bucking at the ~32/34* of locked out timing you might be tempted to run.
More likely, your minimum speed will be much higher. Toeing the clutch is not a good option.

With closed chamber alloys and tight-Q, you can, and to be competitive, will have to, run more cylinder pressure. But on the street,with a big cam, this quickly feeds back into the 4-speed and at "normal" timing, will produce bucking.

Bucking, if you don't know it, is what happens when, as the rpm drops, the individual power pulses are so strong, that they hammer the driveshaft mercilessly, 4 times per engine revolution; and the trans/rear gears multiply this by their combined ratios. It begins softly, and rapidly builds because the pulses are delivered to the chassis, to the floor, to your right foot, and into the gas pedal. The nose of the car will rise and fall lock-step with the pulses and resembles a bucking horse. Once it starts it does not stop by itself, you have to clutch it. This gets really annoying, so you end up with your left foot slipping the clutch, and depending on what clutch that you are running, that can get real old real fast; not to mention all the heat going into the flywheel..
So after the first session or two, your desire to drive it on the street will be much diminished.
There is no cure for bucking if you have a 4-speed, only the tempering of it. The primary method of easing it is retarded timing. This reduces the cylinder pressure by lighting the fire late and the pressure chases after the fast falling piston, thus reducing the torque into the clutch.
The second trick is reduced cylinder pressure,see above. Timing is just way cheaper and easier than new pistons.
And the third easement is a smaller cam, with less overlap and a longer power cycle..
Of course all three of these are counter to racing.

The closest to a cure, is a hi-stall TC...... which is not counter to racing,lol. Most or all of the bucking will get lost in the fluid coupling.

243@.050 is not that big a cam for a 440. I ran the Dc 292/292/108 in my 367, which measured ~248@.050, and that is when I ran into bucking. And that is when I purchased the dash-mounted, dial-back, timing device. Mine has a range of 15* . I used it to develop my timing curve, which ended up being 12/14 idle timing, and I set the device to be able to retard the timing to 5*. My cylinder pressure with that cam was well over 180psi. But at 5* it was driveable. But in the overall picture, as a streeter, I quickly tired of that cam and sold it to a racer who loved it.
Two cams later I was at 230@.050, and a lil less pressure, and now, the DB timing device allows 500/550 rpm, and with 3.55s and 27s this makes 3.7 to 4.0mph possible for me. At 550, the engine has just enough power to pull itself on flat,level,hard ground, on the curb-idle screw, so no input from my right foot to muck it up. It can pull itself up a gentle incline but when she drops to 500, stalling is imminent,lol. I just dial in a couple more degrees of timing and up she crawls, but once over the bump, I gotta dial it back rightaway or bucking is imminent.lol.
Car has gone 93 in the Eighth, with this 230* cam, at 3457 pounds and at 930 ft, with a 60ft of 2.4 and change.
Hope this helps,lol.

sbh126 said:

Its been quite a while since I’ve made a post on here as I’ve been stationed in In Japan for the last three and a half years and my Duster has been in government storage. Anyways, I should be back in the states in the next few months and back to working on my car. I’m by no means an engine builder so I’d like to get some opinions on my current build and where improvements can be made to get some more power. I’d really love to get into the low 10’s. The car probably weighs around 3300 lbs and according to the online calculators I’ll need around 650hp.

Current set-up
440 with stock forged crank and reconditioned LY rods, Icon forged pistons, and unmodified stealth heads giving me 10.23:1 compression and .039 quench. Edelbrock RPM intake, Atomic EFI (rated to 620HP), and 2” fenderwell headers to 3.5” collector. MSD Digital 6AL and all MSD ignition components. Currently running a Comp solid roller cam with 110 LSA, 243* duration at .050, .550 lift but using 1.6 rockers so actual lift is around .587 and slightly more duration. 4 speed, 3.55 rear gear, and 26x11 M/T street radials. I’m not sure what kind of power I’m currently making and I’ve never had it to the track with this engine. Runs on 91 octane. With my current cam and heads my calculated dynamic compression is 7.77:1 and 156 cranking PSI.

Future plans
If the Atomic EFI system can’t keep up I’ll switch back to an 850 CFM Holley carb.

I’ve got some weight reduction plans.

I’m thinking about ordering the Trickflow 240 CNC ported heads and switching to a single plane Victor intake. I’m sure this will increase power but I’m concerned it will move my powerband up beyond 6500 RPM above where I’m comfortable spinning it with LY rods. I want to keep the engine somewhat streetable. The head change would give me 10.82 static compression. Calculated Dynamic compression would be 8.2:1 and 168 cranking PSI.

I’ve considered ordering a more aggressive cam but again, I don’t want to have to rev above 6500 in order to take advantage of it.

Is there anything I’m not considering? Is 650 hp even a reasonable goal on 91 octane? Where is my money best spent?

Click to expand...

Shed weight, I run mid To high tens with a stroked 440 very consistently. Shedding weight is a great cost saving measure. Fiber glass is your friend. Your platform looks like a great starting point. AJ is spot on as always. We call it hammering but call it whatever you want , hammering, bucking, bunny hopping it is just a plain speed and equipment killer. And I am just north of 630hp on 91 octane. Disclaimer, I switched to EFI about two years ago. Frankly I think I gave up just a bit of HP but more than made up for it with consistency. Weather tunes at track are an art form. I have zero regrets. Everything about the car is better with EFI. My carb tuning skills are suspect at best and the EFI hides my ineptitude.

sbh126 said:

I just tried to look this up and found a Hotrod article where they tried to repeat Trickflows test and ended up with 560hp. They were using a single plain intake and like you said the cam was very similar to mine and they had peak power at 5800. So I guess I don't need to worry too much about the power band moving out of reach. Also, the article didn't mention anything about porting so the CNC ported heads I'm looking at might make a bit more power.

I'll have to take a look at the available stroker kits. If I'm looking at buying rods and paying for a re-balance anyway it might be worth my time to go ahead and replace the whole rotating assembly. I appreciate the insight.

Click to expand...

Yeah all dynos seem to be different. By the way All trickflow 240 & 270 are cnc ported.
Andy f made I think 720 hp with his 240s & 750 with 270s but it was a dyno engine with a decent oiling system & pretty expensive parts, proffesional ported (Wilson) intake & that motor was pump gas 10.6 cr

I do have a nitrous system installed but have yet to use it. I think it was good up to a 300 shot which is more than I’d ever need. I’ve got forged pistons and the rings were gapped for nitrous when I installed them. Though I could only find chrome moly rings in .040 size. I think if I get it tuned appropriately and then use nitrous to get me to 650hp I would be happy. I think I want to avoid doing a stroker as that would be a complete rebuild on a basically new motor.

I’m thinking the rods will be fine as long as I keep the rpm’s low. It seems to me that rod failure is more related to RPM and piston weight than horsepower of the motor. I would guess the most stress is put on the rod during the intake stroke as the crank is pulling the piston downward. I read somewhere about a 1000hp supercharged 440 using six pack rods and not having any issues. It made peak power at 5000 RPM. Where as there are plenty of instance like Hot Metal mentioned where the rod failed at much less horsepower but at a higher RPM. Am I crazy or does this make sense?

The cam I have now never gave me any problems with bucking or needing to feather the clutch with the 25.8” tires and 3.55 gear. Once I get the taller tires and deeper 4.10 gear my overall ratio should be very close to the same so I think the setup will remain street able. Although if I go through with the head change and bump up the compression, I guess that could change. If I end up having problems I'll look into an in dash timing controller. It might be nice to have with as hot as it gets in Arizona where I'm headed. I’m sure I could have faster, more consistent times with an automatic but I love that 4 speed so much it’s just not worth it to me to switch over. Same reason I still have the front bench seat. It weighs a ton but I couldn’t picture putting anything else in there.

I do have plans to pull some weight off the car. I’m going to gut the doors as much as possible keeping them stock looking and functional. I also will be putting on fiberglass fenders and hood as well as some lighter brakes. I’ll probably gain about 40lbs back when I put the roll bar in it. I know I can’t have my cake and eat it so to speak but I don’t want to drive a completely gutted car around. I’ll remove as much useless weight as possible without sacrificing functionality and whatever it weighs is what it weighs.

sbh126 said:

Its been quite a while since I’ve made a post on here as I’ve been stationed in In Japan for the last three and a half years and my Duster has been in government storage. Anyways, I should be back in the states in the next few months and back to working on my car. I’m by no means an engine builder so I’d like to get some opinions on my current build and where improvements can be made to get some more power. I’d really love to get into the low 10’s. The car probably weighs around 3300 lbs and according to the online calculators I’ll need around 650hp.

Current set-up
440 with stock forged crank and reconditioned LY rods, Icon forged pistons, and unmodified stealth heads giving me 10.23:1 compression and .039 quench. Edelbrock RPM intake, Atomic EFI (rated to 620HP), and 2” fenderwell headers to 3.5” collector. MSD Digital 6AL and all MSD ignition components. Currently running a Comp solid roller cam with 110 LSA, 243* duration at .050, .550 lift but using 1.6 rockers so actual lift is around .587 and slightly more duration. 4 speed, 3.55 rear gear, and 26x11 M/T street radials. I’m not sure what kind of power I’m currently making and I’ve never had it to the track with this engine. Runs on 91 octane. With my current cam and heads my calculated dynamic compression is 7.77:1 and 156 cranking PSI.

Future plans
If the Atomic EFI system can’t keep up I’ll switch back to an 850 CFM Holley carb.

I’ve got some weight reduction plans.

I’m thinking about ordering the Trickflow 240 CNC ported heads and switching to a single plane Victor intake. I’m sure this will increase power but I’m concerned it will move my powerband up beyond 6500 RPM above where I’m comfortable spinning it with LY rods. I want to keep the engine somewhat streetable. The head change would give me 10.82 static compression. Calculated Dynamic compression would be 8.2:1 and 168 cranking PSI.

I’ve considered ordering a more aggressive cam but again, I don’t want to have to rev above 6500 in order to take advantage of it.

Is there anything I’m not considering? Is 650 hp even a reasonable goal on 91 octane? Where is my money best spent?

Click to expand...

sbh126 said:

I do have a nitrous system installed but have yet to use it. I think it was good up to a 300 shot which is more than I’d ever need. I’ve got forged pistons and the rings were gapped for nitrous when I installed them. Though I could only find chrome moly rings in .040 size. I think if I get it tuned appropriately and then use nitrous to get me to 650hp I would be happy. I think I want to avoid doing a stroker as that would be a complete rebuild on a basically new motor.

I’m thinking the rods will be fine as long as I keep the rpm’s low. It seems to me that rod failure is more related to RPM and piston weight than horsepower of the motor. I would guess the most stress is put on the rod during the intake stroke as the crank is pulling the piston downward. I read somewhere about a 1000hp supercharged 440 using six pack rods and not having any issues. It made peak power at 5000 RPM. Where as there are plenty of instance like Hot Metal mentioned where the rod failed at much less horsepower but at a higher RPM. Am I crazy or does this make sense?

The cam I have now never gave me any problems with bucking or needing to feather the clutch with the 25.8” tires and 3.55 gear. Once I get the taller tires and deeper 4.10 gear my overall ratio should be very close to the same so I think the setup will remain street able. Although if I go through with the head change and bump up the compression, I guess that could change. If I end up having problems I'll look into an in dash timing controller. It might be nice to have with as hot as it gets in Arizona where I'm headed. I’m sure I could have faster, more consistent times with an automatic but I love that 4 speed so much it’s just not worth it to me to switch over. Same reason I still have the front bench seat. It weighs a ton but I couldn’t picture putting anything else in there.

I do have plans to pull some weight off the car. I’m going to gut the doors as much as possible keeping them stock looking and functional. I also will be putting on fiberglass fenders and hood as well as some lighter brakes. I’ll probably gain about 40lbs back when I put the roll bar in it. I know I can’t have my cake and eat it so to speak but I don’t want to drive a completely gutted car around. I’ll remove as much useless weight as possible without sacrificing functionality and whatever it weighs is what it weighs.

Click to expand...

Do you have caltracs & good springs?
Are you mini-tubbed & springs relocated?
You have a 300 shot on the car already, what the....you already have the low 10s car it's now up to you to drive it there. I had ran a 3.91 gear with 27 inch 295 50 15 on a charger back some years. It was unacceptable on anything over 10 freeway miles. I think my dakota r/t with 3.92 at 70 mph is unacceptable in o/d but I think there's a problem with the governor pressure switch now. My ram with 3.55s & 30 inch tires will cruise at low rpm in o/d.
Is your 4 speed a close ratio or a o/d ?

sbh126 said:

I do have a nitrous system installed but have yet to use it. I think it was good up to a 300 shot which is more than I’d ever need. I’ve got forged pistons and the rings were gapped for nitrous when I installed them. Though I could only find chrome moly rings in .040 size. I think if I get it tuned appropriately and then use nitrous to get me to 650hp I would be happy. I think I want to avoid doing a stroker as that would be a complete rebuild on a basically new motor.

I’m thinking the rods will be fine as long as I keep the rpm’s low. It seems to me that rod failure is more related to RPM and piston weight than horsepower of the motor. I would guess the most stress is put on the rod during the intake stroke as the crank is pulling the piston downward. I read somewhere about a 1000hp supercharged 440 using six pack rods and not having any issues. It made peak power at 5000 RPM. Where as there are plenty of instance like Hot Metal mentioned where the rod failed at much less horsepower but at a higher RPM. Am I crazy or does this make sense?

The cam I have now never gave me any problems with bucking or needing to feather the clutch with the 25.8” tires and 3.55 gear. Once I get the taller tires and deeper 4.10 gear my overall ratio should be very close to the same so I think the setup will remain street able. Although if I go through with the head change and bump up the compression, I guess that could change. If I end up having problems I'll look into an in dash timing controller. It might be nice to have with as hot as it gets in Arizona where I'm headed. I’m sure I could have faster, more consistent times with an automatic but I love that 4 speed so much it’s just not worth it to me to switch over. Same reason I still have the front bench seat. It weighs a ton but I couldn’t picture putting anything else in there.

I do have plans to pull some weight off the car. I’m going to gut the doors as much as possible keeping them stock looking and functional. I also will be putting on fiberglass fenders and hood as well as some lighter brakes. I’ll probably gain about 40lbs back when I put the roll bar in it. I know I can’t have my cake and eat it so to speak but I don’t want to drive a completely gutted car around. I’ll remove as much useless weight as possible without sacrificing functionality and whatever it weighs is what it weighs.

Click to expand...

That front bumper & brackets could weigh 80 pounds, on the nose, you'd do wonders by making that fiberglass. If you could find some earlier 69-70 doors they're considerably lighter. Oh yeah what torsion bars do you have ? Because weight transfer is alot of the battle with a heavy nosed car

I’ve got the Mopar Performance replacement springs and I’m planning on putting caltracks on. Hopefully that set up will work for me. If needed I’ll switch to the caltrack mono leaf springs. Mini-tub and spring relocation are happening as soon as I get back as well. I’ve got the 11” wide wheels on now but they stick out about an inch.

The 4 speed is a 1:1 ratio final drive. I have an aluminum overdrive 4 speed as well but it won’t handle the abuse from what I’ve been told. I’d really like to get a gear vendor overdrive but I’ve got other priorities on the car first.

I cut a ton of metal out of the bumpers and removed those huge bumper shock absorbers as well. Once I can find some aluminum bumper brackets I’ll be able to remove the last few pounds. I like the look of the chrome bumper so I’ll keep those but all the steel behind them has been removed. I’m hoping I’m lighter than 3300# but I figure that’s a safe estimate. Had it weighed a few years and it came in at 3450 without driver and full tank of gas. This was before cutting any weight out and I think the scale was a touch on the heavy side.

I’ve got big block torsion bars installed but still have the slant six bars so I’ll be putting them back in. I’m also considering removing the sway bar but I’ll have to see how this affects it on the street. As for the doors I’m hoping to find a usable set and go to town with a hole saw (see photo below). I can remove the crash bars if they’re the later doors and AAR sells a fiberglass door skin for $130 that would save a few pounds.



Overall, it sounds like I’m on the right track I guess. I’ve been trying to figure all this out as I go. I appreciate all the advice.

sbh126 said:

I’ve got the Mopar Performance replacement springs and I’m planning on putting caltracks on. Hopefully that set up will work for me. If needed I’ll switch to the caltrack mono leaf springs. Mini-tub and spring relocation are happening as soon as I get back as well. I’ve got the 11” wide wheels on now but they stick out about an inch.

The 4 speed is a 1:1 ratio final drive. I have an aluminum overdrive 4 speed as well but it won’t handle the abuse from what I’ve been told. I’d really like to get a gear vendor overdrive but I’ve got other priorities on the car first.

I cut a ton of metal out of the bumpers and removed those huge bumper shock absorbers as well. Once I can find some aluminum bumper brackets I’ll be able to remove the last few pounds. I like the look of the chrome bumper so I’ll keep those but all the steel behind them has been removed. I’m hoping I’m lighter than 3300# but I figure that’s a safe estimate. Had it weighed a few years and it came in at 3450 without driver and full tank of gas. This was before cutting any weight out and I think the scale was a touch on the heavy side.

I’ve got big block torsion bars installed but still have the slant six bars so I’ll be putting them back in. I’m also considering removing the sway bar but I’ll have to see how this affects it on the street. As for the doors I’m hoping to find a usable set and go to town with a hole saw (see photo below). I can remove the crash bars if they’re the later doors and AAR sells a fiberglass door skin for $130 that would save a few pounds.



Overall, it sounds like I’m on the right track I guess. I’ve been trying to figure all this out as I go. I appreciate all the advice.

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Yeah, it sounds like you're well on your way, go take the beauty to the track & get a baseline, run it as hard as you feel comfortable. I've heard mono leafs are the best but alot of folks like the super stock spring and level there car out by the d/s torsion bar. Good luck & thank you again for your service