Need to make a decision fast 5.7/6.1/340

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jrlegacy23 said:
I have spare LX manifolds. If you want to try those, I will send them to you; just pay shipping. I would think the jeep ones are too long. If you are mounting them upside down, a set of shorty truck headers may be ideal, but I don't actually know.
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I am not doing the swap. Just was curious is all. I think there are a few threads about this subject on either YB or Theturboforums.
 
PoisonDart74 said:
Bullsh*t, you can do it for under a grand. Do a Magnum swap if you want EFI. Still about a grand. The way your talking about dropping ridiculous coin on projects, your gonna have a hard time with a hemi swap, and you damn sure aren't gonna be done by next summer. Keeping it real homie. Every other response is head in the clouds time. I'll be that guy.
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Good points here...... it will, without a doubt, cost probally three times as much to convert to a EFI modern hemi, as it would to rebuild what you have...But if that's what you want, its cool, go for it!
 
4speeds4me said:
Nutters in Washington. 475HP on the dyno (only cam/spring change on stock 5.7, and utilizing their Hemitronix injection). 3200# car, no OD, 21mpg on the freeway.

I can't remember who it was here, but someone posted they're turning 3500rpm at 65mph, and puling 21mpg. My truck (granted, has OD) weighs 5400# and gets 20+ at 65-75mph...
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That was me - turning 3150 at 60 mph - and its verified against my 318/392 LA stroker making less hp in front of exactly the same drive line - which returned 14 mpg the same trip a year earlier
 
MoparOrNokar said:
Im not looking to change the K member or anything makor like that. I PLAN ON putting my. 727 behind the 5.7
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first point: if the price / work of changing the kmember is too daunting... you probably should skip this kind of dream project. actually the kmember swap makes it easier for you to fit decent exhaust up to your engine. handles better. strengthens a few things that need it (HDK comes with shock support hoops that tie into the frame, etc). gives you a lot more choices for oil pans. stuff like that.

second point: most of the people who get the swap done (actually finish) have purchased a wrecked truck/car and pulled the whole hemi drive train and control harness and swap it over.

if you are going to do this piecemeal expect a way higher pricetag. and longer build time.

on an old school 360 stroker, 408 with a manual trans or lockup converter you will get comparable gas mileage to the hemi. it's not the motor or EFI that gives the 21mpg. it's the lockup converter or OD. the 727 with old type converter is the gas hog. not the engine or the body of the car.

some people have had good results with FAST EFI also instead of using the factory.

also this wont be done "quickly"

dont pull your 360 right away or your car will be just sittin for a couple of years
 
moparlover said:
first point: if the price / work of changing the kmember is too daunting... you probably should skip this kind of dream project. actually the kmember swap makes it easier for you to fit decent exhaust up to your engine. handles better. strengthens a few things that need it (HDK comes with shock support hoops that tie into the frame, etc). gives you a lot more choices for oil pans. stuff like that.

second point: most of the people who get the swap done (actually finish) have purchased a wrecked truck/car and pulled the whole hemi drive train and control harness and swap it over.

if you are going to do this piecemeal expect a way higher pricetag. and longer build time.

on an old school 360 stroker, 408 with a manual trans or lockup converter you will get comparable gas mileage to the hemi. it's not the motor or EFI that gives the 21mpg. it's the lockup converter or OD. the 727 with old type converter is the gas hog. not the engine or the body of the car.

some people have had good results with FAST EFI also instead of using the factory.

also this wont be done "quickly"

dont pull your 360 right away or your car will be just sittin for a couple of years
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Couple things You got wrong:
-most guys doing the swap don't start with a wrecked truck or car. It is beneficial to start with a motor with all accessories, though.
-Rat just posted his huge difference in gas mileage with only a motor swap. No changes to the rest of his drivetrain.
-Aftermarket K does not mean better handling. Some might, but the best handling Mopars have factory K members.


The swap is bolt in with a LA K member, manual or borgeson steering, TTI mounts, and TTI headers.
 
Uhcoog1 said:
Couple things You got wrong:
-most guys doing the swap don't start with a wrecked truck or car. It is beneficial to start with a motor with all accessories, though.
-Rat just posted his huge difference in gas mileage with only a motor swap. No changes to the rest of his drivetrain.
-Aftermarket K does not mean better handling. Some might, but the best handling Mopars have factory K members.


The swap is bolt in with a LA K member, manual or borgeson steering, TTI mounts, and TTI headers.
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i said most of those that finish... not most doing the swap. there's a difference
so you are saying Rat had a lockup converter on an LA engine? or was he using a 904/727?
yes the aftermarker K's do handle better. you are referring to the green brick that was over 10 years ago i think... aftermarket K's also can lower the front 1" and allow for a much wider selection of shocks/spring rates depending on intended use. lack of bump steer is amazing for drag racing. not to mention a huge selection of brake packages once you have the mustang II spindles....

the swap is NOT a drop in. crank sensor, starters, flywheels, controls for lockup converters, power steering / pully stuff there are a ton of mods.

it's ok that you prefer the hemi's nothing wrong there but dont try to sell them on people by playing off the expense involved.
 
MoparOrNokar said:
This spring i bought a 70 duster with a tired mild 360. Now after a summer of my foot on the pedal she is real tired. Im debating on throwing a 5.7 hemi in for performance and economy. I want a street/strip car but i also dont want to pass everything but a gas station.

The guy i bought the car off wants to sell me a 340 with 9.5 pistons, steel crank, with headers and he has a set of edlebrock heads that need to be machined. He wants $4000 for the setup but the way i look at it is thats $4k for a used motor. He claims around 3k miles on the build. I also want more horse than what he claims in that motor. Im shooting for 450hp

Im womdering if someone who has done the 5.7 swap can tell me any pointers they have with problems they ran into and a round about price to do the swap. Im not looking to change the K member or anything makor like that. I PLAN ON putting my. 727 behind the 5.7
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I've done all 3. I used to work in a cylinder head shop in n.j., not far from Raceway Park. Here what I noticed. The 340 with early batton w2 heads, and a .528 mopar cam, made about the same power as a 5.7 with the comp with a medium size comp cam, in the same 1969 Barracuda 727, 3.91. The difference was the 340's power was at a much higher rpm, and the 5.7 wasn't what I would call torquie, but had a much flatter curve, and was a better street engine. (That 340 with a manual trans would be more fun, but not necessarily better ) The pocket ported heads of the hemi flowed much better than the w2 race head, as a matter of fact they flowed better than a 23 degree chevy race head. The hemi's street behavior was much better for daily use. One thing nobody ever talks about is the hemi's cam base circle. The cam base circle of the 340 is about 1.310, and the hemi is about 1.615. So while the two engines might be chosen with cams that appear to be similar-numerically, in duration, and lift, the hemi cam might actually be a lot bigger, but acts smaller, Plus the rocker arm ration is 1.6, and the push rods, are a lot shorter, and lighter, which means there's less weight to move in the top end.
I put 6 years of hard driving on my 340, and eventually melted the mill down, at a grossly excessive illegal speed while racing a Porsche up the blue mountain. ( the fella was some rich guy in a convertible, holding up traffic, while on his cell phone. Once the lanes split into two, and I tried to pass him, he decided it was a race, I thought it was funny to go door to door with him since 3.91 gears at 6500 rpm's, make it tough to use a cell phone. ) When I arrived to where I was going the car never started again, the crank walked, than the motor was sold to that know-it-all from M.A. magazine. ( who stole a carb fro my garage.) The 5.7 had 7 yrs of hard driving, and eventually was sold to an off roader for a jeep, and is still running, granted he change a few internal parts for his application. The 340 holds the hearts of millions, but I think the hemi is a better engine, and your 360 might just need a rebuild, some minor head work, and to pump up the compression a bit. ( they love compression.)
 
P.S. You can get 5.7 engines for a lot less money at Harry's up pull it- Hazelton PA, than the prices people are stating. To flip it another way, the big stroker LA engine from mopar is like 12 grand too. I can get a 5.7, and build a 392, or 416 for less than a mopar crate. So really the price is subjective.
 
moparlover said:
i said most of those that finish... not most doing the swap. there's a difference
so you are saying Rat had a lockup converter on an LA engine? or was he using a 904/727?
yes the aftermarker K's do handle better. you are referring to the green brick that was over 10 years ago i think... aftermarket K's also can lower the front 1" and allow for a much wider selection of shocks/spring rates depending on intended use. lack of bump steer is amazing for drag racing. not to mention a huge selection of brake packages once you have the mustang II spindles....

the swap is NOT a drop in. crank sensor, starters, flywheels, controls for lockup converters, power steering / pully stuff there are a ton of mods.

it's ok that you prefer the hemi's nothing wrong there but dont try to sell them on people by playing off the expense involved.
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You're being ridiculous. Don't speak in absolutes when you've never done any of the things you speak of.

I will say it again, as I'm speaking from experience:
-Most of the guys who have completed the swap on this site do not start with a donor car. Just a motor, hopefully with all the accessories and intake.
-The factory K member provides for great suspension geometry. Show me where a k member swap car has outrun the hotchkis eMax Cuda. Or don't, because it hasn't happened. Or better yet, you show up with a coil over car and come run against my factory k frame car on a road course. To me, they're both just spring packages that keep the rubber on the road. The car doesn't care what spring is used- it only cares what the spring and shock rates are, and what the geometry is. I agree the coil overs provide for more room. But I wholeheartedly disagree with the statement that a coilover k frame swap provides for superior suspension.
-I don't remember all of rat's build specs. Based on what he typed in this thread, everything was the same but the motor. Mileage bumped up significantly. Surprising to me too.
-I specifically said bolt in. Because it is. Bolt in, plug and play, with ~4 wires to connect (or more, depending on which EMS you use).
 
on an old school 360 stroker, 408 with a manual trans or lockup converter you will get comparable gas mileage to the hemi. it's not the motor or EFI that gives the 21mpg. it's the lockup converter or OD. the 727 with old type converter is the gas hog. not the engine or the body of the car.
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Cannot and do not agree with this - as Ive run both types of motor thru a 3400 PTC stall , 727 full race trans and 8&3/4 diff.

14mpg vs 21mpg highway over two hundred miles st 70deg - 80 deg F

If I was asked what made the difference, Id say infinitely superior combustion in a better designed alloy head, better breathing through much better designed ports, MAP advance ( my old LA ran a mech advance dist only) , and superior ignition characteristics plus a smaller hyd roller camshaft making more power than a larger flat tappet.

Id be appalled if a modern motor only showed the MPG return of a 50 year old design - race spec or otherwise.
 
PS - A better built LA with vac advance and alloy heads would show better MPG Im sure....but still nowhere near the efficiency of the G3......so converter differences are nowhere near the whole story...
 
Rat Patrol said:
Cannot and do not agree with this - as Ive run both types of motor thru a 3400 PTC stall , 727 full race trans and 8&3/4 diff.

14mpg vs 21mpg highway over two hundred miles st 70deg - 80 deg F

If I was asked what made the difference, Id say infinitely superior combustion in a better designed alloy head, better breathing through much better designed ports, MAP advance ( my old LA ran a mech advance dist only) , and superior ignition characteristics plus a smaller hyd roller camshaft making more power than a larger flat tappet.

Id be appalled if a modern motor only showed the MPG return of a 50 year old design - race spec or otherwise.
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I used a carb set up on my hemi. It had the older XFI273 cam, and a 2400 stall converter. I got 17 MPG city to 25 Highway, I put 60,000 miles on my 69 Barracuda before it got T boned. Since I was using a 727 trans, and 3.23 gears, as you can imagine, that equates to 3 grand, or more just to drive on the interstate, and keep up with traffic. I hate driving alone, if there's a car a mile ahead on me, I need to rush up and be 150' behind him. So I drive 70-75 MPH. Most of my driving was from the coal region of PA, to the Jersey shore where my Mom lives. I did install a 180 degree thermostat, although I resigned myself to the fact that, no matter what I did the car would run at 210 spot on all the time. I think I tuned it once with a vacuum gauge, and changed the plugs once. It was rock solid reliable. As far as somebody else put it " You need a BFH to install it," That's true, and it's not. In a 1968 Barracuda with 340 Torsion Bars, It was a matter of lifting it over the Radiator support, and dropping it in. No harder than a 440. I did have to manipulate the engine engine a bit toward the passengers side, and I had to push on the trans tail shaft with my feet, while trying to bolt it up. ( that worried me, but it never amounted to anything.) I converted it from 340, to hemi in 3 days, and it was on the street. The hardest part was tapping into the start, and run wires, and figuring out where I wanted to install the electric fuel pump.
On the reverse side of the coin, I work all winter through the snow to change the suspension, and build my 75 Duster, and I'm still having headaches. One inch Torsion bars do not clear my TTI headers without major squashing. ( Although if you call TTI, I got the very first set of headers, and A body mounts. 2007 XV motorsports.) So, TTI say they may have changed them since. My Carb set up will not fit under my hood without a scoop. I can't use the angled oil filter adapter, the passenger motor mount is flush with the oil filter mount. I've heard some people say, they had trouble installing the starter. I just had to shave an ear off the block. I can change my starter from above the engine, if I put a bit of force on my brake lines. I did have to move the proportioning valve back an inch to clear the headers. In my 69, I had to drill one hole in the passenger side firewall to bolt the transmission in, on the 75 I didn't. All in all, each A Body is a variation of the same specs, but not very consistent. Still knowing what I learned on the first install, it took 3 hours rather than 1 to pop the engine in, and slide it aside. The rest of the car is a F**kin' nightmare although.
 
Uhcoog1 said:
Regarding fuel system:
Carter 4600HP $115
BC Bronco's fuel accumulator - $70
Walbro GSL392 $110
Wix. 33737 - $40
Fittings, etc - $100
Cheapest EFI fuel system that will handle 600 hp
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How much of a whine is coming out of that Walbro?
If it's too loud it would drive me crazy on a Houston-Dallas trip
 
Come hear it. I'm in houston.

There is noticeable whine.

Side note: I'm going to change my fuel system as soon as the new efi stamped tank is available from tanks inc. I'm very excited about that new offering.
 
If that was available when I did my intank pump I would've jumped all over it. Plus they're 18 gallon capacity. Instead I did it my weigh and now a big mass of aluminum hanging under my rear license plate lol!
 

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Uhcoog1 said:
http://www.tanksinc.com/index.cfm/page/ptype=results/category_id=146/mode=cat/cat146.htm

$245 for an efi tank. Count me in!

5" baffle running the width of the tank. 1 gallon fuel bowl in tank that pump sits in. Looks great to me.
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i'd like to see that bowl and how its filled/stays filled.

ugh they are MAKING new tanks. You would think they would just pop one with a some OEM size ring and sell a modded OEM canister to fit a plastic reservoir with venturi pump. ala like this~ish http://www.gearhead-efi.com/gm-ecm-pcm-conversion/in-tank-fuel-pump-conversion.html

EDIT: Every good idea has someone somewhere already doing it: http://www.vaporworx.com/
 
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