My 360 build.

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89on35s

Inferno Red Duster
FABO Gold Member
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I am going to pick up a 360 short block this week. I got it for what I feel is a super sweet deal for what I am getting. It is a .030 over 360 block with flat top pistons and an MP 508 cam. It was raced only a couple times by the guy who built it (a friend of a friend) before he sold the car it was in. The builder is a long time Mopar guy from the area and I have reason to believe he would have done a very good job on this motor. The buyer of the car was dead set on having a 340 so he yanked the 360, pulled the 2.02 X heads off it and stored it in a dry shop for 10 years. Nothing is seized, a good friend looked at it for me. I will disassemble and clean it all. Likely install new bearings and rings, and build it from there. I will get pictures, numbers and measurements as soon as I pick it up.

I will be putting it in my 74 Duster with an A-500 Trans and currently a 3.23SG 8 ¼ rear. I use this car primarily as a cruiser but if it could make the low 13s or high 12s I would be ecstatic. It needs to idle well, cruise at 2000 to 2400 for extended periods, but go like skin hell when asked to. I will keep my A-500 which my tranny guy says he built to easily handle 500 hp in my car. Oh, and I have and will keep my Air Conditioning on the car too. My suspension is not drag race suspension at all. I have 1.03 torsion bars, front and rear sway bars, Bilstein RCD shocks, tubular UCAs all for the nice handling feel and I don’t want to give that up either. These are my goals for the car.

I need advice on the top end and cam that will get me there. I have an Edelbrock Performer 318/360 intake and a 670 Street Avenger Holley on my current 360 but am not dead set on using them, however if I can, I will. I have stock Mopar ignition which I will keep if possible since I hope a Sniper EFI with timing control will be in my future but I am not thinking about that now.

I am not committed to any specific gear ratio, but I will end up with a 28” tall 10” wide tire in the back when I am done. Likely a 275/60-15 Drag radial. I have an A-body width 8 ¾ I will build up over the winter with whatever gear ratio I decide on. I will definitely install whatever convertor I need to but I am not sure what will be available as mine is a lock up. I assume there are custom ones out there for $$.

I will go with whatever head is best value, I want Edelbrock or better yet the new Trick Flow Aluminum but is there a cheaper Iron alternative that would get me there. I have a bare set of J heads, a currently operating set of mid 70s 360 heads and a set of stock mid 80s 360 heads in my possession now and will definitely port them myself or have them done. I won’t waste my time though if it won’t meet my goal.

From what I have researched, the MP 508 cam is not what I want for my intended use. It should be worth something to sell I hope (more likely I'll squirrel it away ona shelf and forget I have it). I’ll likely go to a hydraulic roller. And likely it will come from a custom cam grinder (Racer Brown etc.)

What am I missing? Where will I fall short? This is my first time at something like this. As long as I’ve had my Duster, it has had the motor it came with and it worked OK so I left it alone. Any comments you have are appreciated. Oh, and I did research old threads for a while and got some great ideas but I still felt I wanted to start my own for my particular situation. I’m not chasing a horsepower number, just good drivability/cruisability and a decent time slip.

Cley
 
Build something like this. I started with a 360. It's now a 408 6 Pack. Just a thought?

IMG_24951.jpg
 
Build something like this. I started with a 360. It's now a 408 6 Pack. Just a thought?

View attachment 1715186801

Completely no help showing off the eye candy that should be installed in your ride and running.
I am going to pick up a 360 short block this week. I got it for what I feel is a super sweet deal for what I am getting. It is a .030 over 360 block with flat top pistons and an MP 508 cam. It was raced only a couple times by the guy who built it (a friend of a friend) before he sold the car it was in. The builder is a long time Mopar guy from the area and I have reason to believe he would have done a very good job on this motor. The buyer of the car was dead set on having a 340 so he yanked the 360, pulled the 2.02 X heads off it and stored it in a dry shop for 10 years. Nothing is seized, a good friend looked at it for me. I will disassemble and clean it all. Likely install new bearings and rings, and build it from there. I will get pictures, numbers and measurements as soon as I pick it up.

I will be putting it in my 74 Duster with an A-500 Trans and currently a 3.23SG 8 ¼ rear. I use this car primarily as a cruiser but if it could make the low 13s or high 12s I would be ecstatic. It needs to idle well, cruise at 2000 to 2400 for extended periods, but go like skin hell when asked to. I will keep my A-500 which my tranny guy says he built to easily handle 500 hp in my car. Oh, and I have and will keep my Air Conditioning on the car too. My suspension is not drag race suspension at all. I have 1.03 torsion bars, front and rear sway bars, Bilstein RCD shocks, tubular UCAs all for the nice handling feel and I don’t want to give that up either. These are my goals for the car.

I need advice on the top end and cam that will get me there. I have an Edelbrock Performer 318/360 intake and a 670 Street Avenger Holley on my current 360 but am not dead set on using them, however if I can, I will. I have stock Mopar ignition which I will keep if possible since I hope a Sniper EFI with timing control will be in my future but I am not thinking about that now.

I am not committed to any specific gear ratio, but I will end up with a 28” tall 10” wide tire in the back when I am done. Likely a 275/60-15 Drag radial. I have an A-body width 8 ¾ I will build up over the winter with whatever gear ratio I decide on. I will definitely install whatever convertor I need to but I am not sure what will be available as mine is a lock up. I assume there are custom ones out there for $$.

I will go with whatever head is best value, I want Edelbrock or better yet the new Trick Flow Aluminum but is there a cheaper Iron alternative that would get me there. I have a bare set of J heads, a currently operating set of mid 70s 360 heads and a set of stock mid 80s 360 heads in my possession now and will definitely port them myself or have them done. I won’t waste my time though if it won’t meet my goal.

From what I have researched, the MP 508 cam is not what I want for my intended use. It should be worth something to sell I hope (more likely I'll squirrel it away ona shelf and forget I have it). I’ll likely go to a hydraulic roller. And likely it will come from a custom cam grinder (Racer Brown etc.)

What am I missing? Where will I fall short? This is my first time at something like this. As long as I’ve had my Duster, it has had the motor it came with and it worked OK so I left it alone. Any comments you have are appreciated. Oh, and I did research old threads for a while and got some great ideas but I still felt I wanted to start my own for my particular situation. I’m not chasing a horsepower number, just good drivability/cruisability and a decent time slip.

Cley

So you want to make a mixed bag of **** run fast without compromise?

FWIW, that 292 is what MP recommended to use for the 12’s. So you should buck what the engineers have figured out and crap on there heads. Excellent move! Good for you to blaze new trails on what works. You da man!

Double check the “12 second “ sticky thread in the racers forum. Ignore the fact you have a OD trans and copy a build. Use the build with the least amount of cam and heaviest car weight close to yours.
 
Completely no help showing off the eye candy that should be installed in your ride and running.


So you want to make a mixed bag of **** run fast without compromise?

FWIW, that 292 is what MP recommended to use for the 12’s. So you should buck what the engineers have figured out and crap on there heads. Excellent move! Good for you to blaze new trails on what works. You da man!

Double check the “12 second “ sticky thread in the racers forum. Ignore the fact you have a OD trans and copy a build. Use the build with the least amount of cam and heaviest car weight close to yours.
no need to be rude m8 show some kindness no room in this word to be a dick because somebody wants to do something and you disagree with their idea
 
Sorry you took it that way because I was thinking sarcasticly in a way. Disagree? Are you sure about that? Better think again and stop assuming.
Though, A little bit of both. For sure. So, straight up, why would you ignore what Mopar has written out for you for decades?

Do you think the engineers are stupid or your just smarter?

Does adding the OD trans twist your brain up that much? No worries, ignore that fact and build as a 3 spe and then enjoy the press of a button OD feature.

OD multiplied by the gear ratio equals final drive ratio. 4.30 X .69 = 2.96. Is that a good ratio for you?

Any more math you want me to do? (LMAO!)

But don’t worry, you’ll know for sure when I’m being a dick to you.

FWIW, again, double check the stick threads in the racers forum.

Also, what are you doing for a converter?
 
Hey Cley
Aluminum heads and very high compression can help you meet all you goals, with that od trans, and maybe even with those 3.23s........... And more. I know, because I built one.
The OD trans opens up a whole new world for you. And
the high cylinder pressure can make up for at least one cam size. And
When you marry them all together, look-out!
But I gotta tell ya. If you build it right, you will be wanting more, and then the 3.23s will be the first to go. With a .69overdrive ratio, there really is no street gear that you cannot run. I even ran 4.88s and 5.38s for a short time. But don't get carried away,lol, because you will end up with a useless first gear, cuz you just can't hook street tires with street suspension.
Because you have that od, and because the low gear in it is 2.74, it is easy to get enough TM (Torque Multiplication) for nice street launches. This means you can optimize second gear instead, cuz most of that combo's life is gonna be spent in second gear....... am I right? That also means you can optimize the engine for that gear.
With that kindof thinking, it's easy to see that the 292/508 cam is just way off for the combo; cuz the power peak can be as high as 5800, and you might go there once on the way to 65mph..... and your tires are gonna be spinning the entire time. And of course the fuel-economy with that cam is atrocious; YES, even with the overdrive, cuz the engine will be stuck at a very inefficient rpm. I know cuz I built one. So you are right to pull it, IMO.

So think about this;
For a starter gear 9 or 10, to 1, is usually plenty, calling for a 3.55 ratio minimum.
For cruising, 2100 is not too much, calling for about 3.91s to get 65=2100 in loc-up with 28s.
So really any ratio in that range will be sweet. Now lets look at second gear with say 3.91s.
The final drive ratio in 2nd will be 1.54 x 3.91= , so 32mph will be just 2430, pretty sneaky. On the downshift into first, the Rs will jump to 4320, pretty close to peak-torque, and your Duster will jump! Now it's up to the cam to carry you to 60 mph, which is gonna be about 4600 in second. Hmm, that's not gonna be the quickest way there.
Ok lets regroup with the aforementioned 4.30s, and lets put 27s on the back. This will get you 60=5200. Well that's not great either, but it's a compromise. The cruise is now 65=2400 still doable and the starter is 11.78. So IMO, that is as good as it gets.
So now, you just build your engine to be a powerhouse thru the midrange, with a powerpeak at or a little under 5200, BadaBoom!
That is pie.
I see a 223* cam and 190psi, with a tight Q.
Wait, whatabout 32 mph now? With the 4.30s,I see 2630 at zero-slip in second, changing to 4900@5% slip, on the downshift. Well that looks crappy,lol. But wait, is it? Yes and no. With iron heads you might be getting close to the shift-rpm, but aluminums will stretch it out a few hundred, so that 223* cam will go 6000 easy, so you are good to 39mph, then the shift will bring it down to 3370, so that 223* better pull.
This is where that 190psi comes in.
With open chamber iron heads 160 is pushing it with the best pumpgas. And that would make for lazy acceleration from 3370. But the aluminums will burn any old gas at 180. And will still burn pumpgas at 200 (as attested to by members here). Mine burns 87E10 at 185 with no problems. And if you have never had a 360 at 190psi, man you are in for a treat. People tell me it feels like a big block. IDK, I've never had one.
So as it turns out, that trans with it's very wide ratios, NEEDS the 4.30s to get second gear working. So Rumble hit the nail on the head.
Yes, first will be a little short, but hey, you can use the current TC, cuz your engine with a 223cam and 190psi, will be a BRUTE for torque, just what you need for a streeter.
And the icing on the deal is that the 223 cam and cruise rpm, with a good tune, will get you fantastic fuel economy at 190psi. I know, cuz I built one.
 
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Well danm AJ. Fracking thank you.

In your opinion, how do you think an intake duration of 230@.050 and a tight 2400 converter stall would do. His car is on the heavier side with A/C and who knows what else?

What kind of “High ratio” are you thinking of?
On a Iron headed mill, I’m pushing 9.5-1 max with 1pt. more for aluminum max.
 
I currently have a 230* cam in my 10.7Scr Eddie-headed 367. I run a 3.55 and an A833 with a 3.09 low gear, and a GVOD.
The starter is 10.97, the cruiser is 2.77 with the overdriver making 65=2240.
Second is 32@2710, so I ain't fooling anybody. But I also don't have to downshift.That 367 at 185psi just lights em up.My car is over 3650 with me in it, with about 48% on the rear.

With the 2400TC, I'm liking the 223 cuz it makes even more low-speed torque for that A500. At 10.8Scr, an easy target, the pressure will be close to 185, and the VP will be big-block like at over 160VP. With the 11.78 starter gear, he will be putting more footpounds to the pavement than I do,and mine lites em up easily,at less rpm. And I have made fuel mileage deep into the 20s USg with that 223, and a nearly 50 year old Holley 600VS.
But if Cley was willing to go with a solid, then yes a bit more@.050 would be a treat and the Scr could go down a little to maintain the cylinder pressure. But you can't go much lower than 223, cuz the pressure is climbing fast...... unless you order a long-ramp cam. My 223 was advertised at 270/280/110. I didn't measure it.
That 10.8 is just flat-tops at about .011 down, the 63cc heads and the .028 gasket. Easy peasy, and with Q of .039. Can't get much simpler than that.

My combo was set up to run 10.7/11.0Scr with just a gasket swap........ which is what I ran with the 292/508/108. When I switched to the 223, I installed the .039 FellPros, to keep the pressure around 185. But now, with the 230 cam, the pistons are .005 out of the hole, and the Scr is set up to go 10.7/11.0 with similar pressure. It's still more than the tires can handle. But once past 85, things settle down for the long haul.
 
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I did a 13.30 car on a cheap 360, and true street car (3.23 gears). Cam was MP .455 lift/268/272 duration. Idled like a stock cam. 750 double pumper Holley a LD340 (RPM eddy would work as well). Heads were J heads.
It really don't take that much to go low 13's/high 12's with a 360 in a A-body.
 
Flat top pistons what compression height?- what is your deck clearance?
we need to be able to compute compression with the available heads how close to the ragged edge do you want to be with fuel requirements
check the deck clearance at all 4 corners to make sure you do not need to square the block up
did you say what your weight is?
on your car is the chassis stiffened- do that before adding horsepower
lots of good tips above
get the best head you can afford
maybe a ported midsize head as opposed to a big port head to keep the velocity up
for a hyd in the 230 range comps XE 275 HL would be the target or HR274HR does slightly better Engle K 58 hyd
If HR I'd recommend an inverse radius flank HR from Mike Jones you will need head flows let us know what he says Street Performance | Jones Cams
did you say what headers
what rockers- ask mike if 1.6 esp on the intake would help and what springs
clearance your new heads for 3/8 pushrods
 
aluminum heads and a performer RPm intake. Shoot for 10:1 or 10.5:1.

Not sure if you want a solid or hyd cam. I much prefer solid.

Lunati
30200740 solid

or

Crane
694561 hyd

Those would be my cam choices.

I'd run a 3.91 or 4.10 gear in the back depending on your tire diameter. I run a 4.56 and cruise about 2500@60. I'd like a 4.10 if I had it to do again.
 
All things being equal you will be much happier with an aluminum head in the long run. Also I will only run a solid lifter. Hydr lifters are a crap shoot. If I read it right it’s a stock stroke crank which he intends to reuse. It’s ok to go off the beaten path, but you have to realize you WILL get lost a bunch and it’s expensive. Keep in mind that anything you experiment on has already been done by someone. Learn from the money they lost/wasted.
 
Many alternatives but to give some idea from back in 1981>
My street car, '71 340 Cuda, all stock suspension, 3.55 gears/B&M super holeshot converter, all stock 2.02 headed motor apart from ally dp intake, .484/284 hydro cam and a 750DP+ hdrs ran 13.28's@101+ with 8x26" bias slicks and probably weighed 3600lbs with me, full interior etc...motor made 302 on track fwhp.
 
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Thanks for the replies. For the record, I am not looking to run a “mixed bag of ****”, that is why I am asking for help in this new territory for me. It was my understanding that those engineers recommended combos for different times were more race biased and not really streetable at all. Maybe that is not the case. I am not chasing a specific time, more of a nice balanced set up as AJ is suggesting. I will not put a roll bar in this car but I don’t think I need to worry about going that fast.

As far as the convertor goes, it will be what it needs to be, dependent on the gear I chose. But since I will be losing the 3.23s anyway, if my gear selection will allow me to keep my convertor, that’s money I can spend elsewhere. The 3.23s are definitely out cause with a 28” tire they will cause too low of RPMs at 60mph for me. The 3.23s are about good for the 26.5” tires I have now. 4.30s are really interesting to me, I am just nervous to take that huge jump. However since they will be in an 8 ¾”, a gear swap is an easy deal.

Aluminum heads are definitely where I will go after the recommendations above. If the Trick Flow heads do become available this fall or winter, I will give them a hard look before buying a set of Eddys. Once I decide that, and get my piston depths measured, I can fine tune my CR with head gasket thickness right? Maybe I don’t have enough info to say that yet. I still need to get the piston height measurements.

Other than the requirement to adjust the preload periodically, is there any other down side to solid roller lifters? I understand they don’t float at high RPMs, any other differences?

91 octane is readily available in my area and I don’t have a problem if that is a requirement. Our 91 Premium fuel doesn’t have ethanol added either which I think is another benefit. I know the ethanol wreaks havoc with my 2 stroke snowmobiles.

I have sub-frame connectors in the car already so it should not twist up the body.

I have cheap Patriot 1 5/8” headers and 2.5” mandrel bent exhaust (Summit kit).

I’ll try and get the weight this weekend. I have been wanting to for a while, but never have. It is a full interior car with AC.

I will be going to pick the engine up tomorrow afternoon and I’m off work Friday so I’ll try and get the piston height measurements on Friday. I have a dial indicator but no deck bridge so they will be close but maybe not machinist exact.

I hope I answered all the questions that were asked above. Unfortunately I don’t have all the answers yet, and maybe I should have waited to post this but it kinda feels like Christmas to me going to get this engine. Doesn’t being 43 years old still allow me to be a kid sometimes?


Cley
 
Thanks for the replies. For the record, I am not looking to run a “mixed bag of ****”, that is why I am asking for help in this new territory for me. It was my understanding that those engineers recommended combos for different times were more race biased and not really streetable at all. Maybe that is not the case. I am not chasing a specific time, more of a nice balanced set up as AJ is suggesting. I will not put a roll bar in this car but I don’t think I need to worry about going that fast.

As far as the convertor goes, it will be what it needs to be, dependent on the gear I chose. But since I will be losing the 3.23s anyway, if my gear selection will allow me to keep my convertor, that’s money I can spend elsewhere. The 3.23s are definitely out cause with a 28” tire they will cause too low of RPMs at 60mph for me. The 3.23s are about good for the 26.5” tires I have now. 4.30s are really interesting to me, I am just nervous to take that huge jump. However since they will be in an 8 ¾”, a gear swap is an easy deal.

Aluminum heads are definitely where I will go after the recommendations above. If the Trick Flow heads do become available this fall or winter, I will give them a hard look before buying a set of Eddys. Once I decide that, and get my piston depths measured, I can fine tune my CR with head gasket thickness right? Maybe I don’t have enough info to say that yet. I still need to get the piston height measurements.

Other than the requirement to adjust the preload periodically, is there any other down side to solid roller lifters? I understand they don’t float at high RPMs, any other differences?

91 octane is readily available in my area and I don’t have a problem if that is a requirement. Our 91 Premium fuel doesn’t have ethanol added either which I think is another benefit. I know the ethanol wreaks havoc with my 2 stroke snowmobiles.

I have sub-frame connectors in the car already so it should not twist up the body.

I have cheap Patriot 1 5/8” headers and 2.5” mandrel bent exhaust (Summit kit).

I’ll try and get the weight this weekend. I have been wanting to for a while, but never have. It is a full interior car with AC.

I will be going to pick the engine up tomorrow afternoon and I’m off work Friday so I’ll try and get the piston height measurements on Friday. I have a dial indicator but no deck bridge so they will be close but maybe not machinist exact.

I hope I answered all the questions that were asked above. Unfortunately I don’t have all the answers yet, and maybe I should have waited to post this but it kinda feels like Christmas to me going to get this engine. Doesn’t being 43 years old still allow me to be a kid sometimes?


Cley
Cley, just let me say this (this is just me): You did well on stating a goal that would make you ecstatic, which would be high 12's. No way would I spend 1500 bucks on aluminum heads just to go high 12's. That is an amazing overkill. In fact, 360 smog heads with 1.88's would pop you in the 12's sleep-walking. 430's are an extreme overkill as well (no offense A/J, love ya man). Jumpin' Jehoshaphat!! Aluminum heads/4.30's, Custom converter, and all the fixin's, sounds like your shooting for low 11's. In fact, if you do a compression test on your car now, and it shows good, your current set up, in my opinion, should be well into the 13's, maybe 12's depending on all "exactly" it has in the build.

This is just me, just putting my opinion out there..... using my personal drag strip tested experiences.

OH!!! Yes, be a kid! Enjoy it man, it's a wonderful thing! :)
 
Thanks for the opinion 318willrun. You may be right, and I'll still keep messing with what I have until I get my new motor built. I just hate the fact that I really don't know what I have. It's a stock mid 70s bottom end with stock dished pistons, an unknown cam, stock mid 70s heads. I have no idea how many miles on it. I know it does run strong (in my mind) but building an engine is less of a necessity and more of a desire. Reliable powerful fun cruiser, that's what I want. Powertour is on my bucket list someday and I want to drive right from my home and all the way back. Oh and did I mention? I'm a big child!

Cley
 
Thanks for the opinion 318willrun. You may be right, and I'll still keep messing with what I have until I get my new motor built. I just hate the fact that I really don't know what I have. It's a stock mid 70s bottom end with stock dished pistons, an unknown cam, stock mid 70s heads. I have no idea how many miles on it. I know it does run strong (in my mind) but building an engine is less of a necessity and more of a desire. Reliable powerful fun cruiser, that's what I want. Powertour is on my bucket list someday and I want to drive right from my home and all the way back. Oh and did I mention? I'm a big child!

Cley
oh, by all means I understand, and my above post wasn't to discourage you from buying and building the other 360 at all. Just putting it out there that you don't need to spend tons of unnecessary money to achieve your set goals.
Make sure you make a thread so we can all follow along :)
 
4.30's are not overkill with an overdrive at all!

I run 4.56's and cruise around 2500@60mph.


What diameter tire are planning on?
 
I’ll likely go to a hydraulic roller.
wants 2000 rpm cruze
looks like a freeway/ road/ mountains chassis- I like it
I have 27 inch tire 3:54 gear and OD works fine with 360 magnum
I've run 3.08 with shorter tire and 4.11 with od 27.5 tire
he has to match the cam up with the gear selected -
 
Cley, just let me say this (this is just me): You did well on stating a goal that would make you ecstatic, which would be high 12's. No way would I spend 1500 bucks on aluminum heads just to go high 12's. That is an amazing overkill. In fact, 360 smog heads with 1.88's would pop you in the 12's sleep-walking. 430's are an extreme overkill as well (no offense A/J, love ya man). Jumpin' Jehoshaphat!! Aluminum heads/4.30's, Custom converter, and all the fixin's, sounds like your shooting for low 11's. In fact, if you do a compression test on your car now, and it shows good, your current set up, in my opinion, should be well into the 13's, maybe 12's depending on all "exactly" it has in the build.

This is just me, just putting my opinion out there..... using my personal drag strip tested experiences.

OH!!! Yes, be a kid! Enjoy it man, it's a wonderful thing! :)
Yes this is true, but don’t we all know how just getting to 12.99 turns into just getting to 11.99 and so on and so forth. Room to grow in some of these suggestions.
 
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