5.7 L hemi into a 72 Dodge Demon

Hi everyone

I would love to install a 5.7 l hemi in my demon and get an overdrive trany.

Anyone know of a factory tranny and mount that will fit.

Rick

the 518 will fit with persuasion lol and you will have to customize your mount for the trany i believe. there are a few builds similar to this on here. i will see if i can find them cuz they have a lotta info. welcome to the site to and dont be scared to ask anything
http://www.forabodiesonly.com/mopar/showthread.php?t=59659 http://www.forabodiesonly.com/mopar/showthread.php?t=53074

Hi everyone

I would love to install a 5.7 l hemi in my demon and get an overdrive trany.

Anyone know of a factory tranny and mount that will fit.

Rick
Welcome, and you should find a wealth of info on this site. You can read through my build (Tincup's 63 w/5.7) or 67 Dart Resto with a 5.7 just for starters. The tranny of choice is a 545RFE out of a late model Ram 1500 2WD. This will allow you to use a Diablo tuner to control both the trans and the engine. As for a mount you will have to fab up your own, but it is not that difficult.

Now get to work, we need more porn. Also, as Tin said, read those threads he posted, this will give you some direction and answer some ???'s you may have, but if you need help, as always, we're here for ya.

Here's a Demon that showed up in Michigan with a 6.1L. It sounded great.

Here's a Demon that showed up in Michigan with a 6.1L. It sounded great.

wow that fits nice, you have anymore pics of that demon?

Sure how many would you like. lol

Hi great car, what type of transmission and crossmember did u use for this car, thanks for any help u can give.

wow i love that Demon!

Im using a stock 833 4 speed and a stock crossmemeber

I saw a new hemi package w/o the electronic and it has carbs..seems to me this would be the easiest.

Grassy

What size bell housing r u using. By the way great job

What size bell housing r u using. By the way great job

You can use the LA motor bellhousing with the 5.7. Though, I believe you need an adapter for the flywheel. Perhaps someone else can answer more defiitively.

Good luck on the build and welcome to FABO!!!

LETS HEAR MORE FROM GDEMON PLEASE,,

Im using a stock 833 4 speed and a stock crossmemeber

Gdemon, did you space the bellhousing off the back of the motor to make up for the additional crank offset on the Gen III Hemi? Or just ignore it? Or maybe the replacement flywheel takes that into account.

Hi

No Im using a stock 340 bellhousing with a mopar performance flywheel.

G DEMON what he is asking is,,the hemis all have a longer crank,,and use a spacer between the back of the block and the bell housing,
did you use a spacer or is there a mopar engineered fly wheel to compinsate for the long crank shaft ?

Must use spacer when using an auto.

so a new hemi will bolt up to a 833 four speed bellhousing without an adapter or anything???

Not sure on the sticks.

ive read that all the LA trannies bolt up but the one bolt doesent line up. i think people either drill it out for it to line up or dont use it. i think you need to modify your flywheel or get a specialy made on though.

www.quicktimeinc.com he makes bell's, spacers, modd'd flywheels for manuals and auto's to a GenIII hemi. I bought a 4l65e - 6.1 kit and it was perfect

Yes the mopar flywheel is engineered to compensate for the crank. Im using no spacers and all seems well. I have about 3500 miles on this setup. Im using a roller pilot bearing from a mag motor and had to shorten the input shaft on the trans about 3/4".

very kool that ma mopar has made a fly wheel like that,,,who has the spacer for the auto ?? thanks G DEMON

Im using a stock 833 4 speed and a stock crossmemeberHi, I love the idea for doing this swap. Say, what else is needed besides the engine? Computer, cables, new cooler, new headers, new engine mounts?

Is there a difference between truck and car engines? I mean internal - cam, valves etc?

Do you still have your old parts list? ;-)

I'm located in Germany and this would be the first swap like this. I'm the first here who is using a Toyota 5 speed in a Dart and this swap would make it perfect... ;-)

Thanks a lot...

Sweet looking hemi swap

So what clutch do you use with the Mopar Performance flywheel setup for the 833 GDemon? I'm hoping to do a 5.7 swap and keep my 833 and know about the flywheel and input shaft trimming, but do I need a specific clutch for the new flywheel or would the old clutch on my current small block fit? I know I would need to upgrade the clutch at some point, but if I could at least get the car on the road with the parts I have that would be nice. Making up a big spreadsheet now of all the parts and costs I expect to run into, but I'm not yet sure what all is required and what is optional.

So what clutch do you use with the Mopar Performance flywheel setup for the 833 GDemon? I'm hoping to do a 5.7 swap and keep my 833 and know about the flywheel and input shaft trimming, but do I need a specific clutch for the new flywheel or would the old clutch on my current small block fit? I know I would need to upgrade the clutch at some point, but if I could at least get the car on the road with the parts I have that would be nice. Making up a big spreadsheet now of all the parts and costs I expect to run into, but I'm not yet sure what all is required and what is optional.


I posted this in the other thread also.

I tried the Truck Flywheel in mine and it wouldnt fit inside the stock bell housing. I used the mopar performance one. I have done 2 Hemi 4 speed cars and used the Center force dual friction disk and had bad vibration problems. I thought it was the flywheel because the pressure plate and disk were from my 340 and had no problems. After taking the pressure plate with me to the machine shop just in case they told me that they dont even sell the centerforce anymore beacuse of the vibration problems they have and told me it was probably that and not the flywheel. Sure enough the flywheel was out .25 g and the pressure plate was out 50 g. I asked him why he thought the centerforce was fine in the 340 and not the hemi he said maybe it was because the hemi has a much lighter rotating assembly. I ended up buying a hays and all has been great since.

ive never heard of these problems your talking about with a center force,,tons of guys run them encluding me,,,i have been for 12/14 years now,,,what hays are you running??? the last hays i had,,still have it in a box,,was an old school pressure plate and you need a big giant leg to push the pedal,,made the fire wall flex,,,

GDemon, is that Hays setup you are currently running the one sold here http://www.mopartsracing.com/parts/57hemi.html by any chance? I looked up the pressure plate part number on Google and one place listed it as a Hays, otherwise I didn't find any direct branding. I didn't know if Mopar Performance made one or not, so I wasn't sure if it might be theirs. If it isn't what you are using, has anyone used this setup before?

ive never heard of these problems your talking about with a center force,,tons of guys run them encluding me,,,i have been for 12/14 years now,,,what hays are you running??? the last hays i had,,still have it in a box,,was an old school pressure plate and you need a big giant leg to push the pedal,,made the fire wall flex,,,


Right i have been using centerforce for 10 years and had that same pressure plate in my demon for 5 years and never had a problem with it until i put it behind the hemi. I think the machine shop guy is right that the hemi's rotating assembly is alot lighter then the old motors and it is much more sensitive. All I know its like a whole different car with the hays in there.

GDemon, is that Hays setup you are currently running the one sold here http://www.mopartsracing.com/parts/57hemi.html by any chance? I looked up the pressure plate part number on Google and one place listed it as a Hays, otherwise I didn't find any direct branding. I didn't know if Mopar Performance made one or not, so I wasn't sure if it might be theirs. If it isn't what you are using, has anyone used this setup before?

No mine is a three finger pressure plate. I just ordered one from summit for a 10 1/2" mopar 23 spline

I may have read this in another thread but can't remember, what clutch setup are you using GDemon? Did you manage to keep the stock mechanical linkage or did you do a hydraulic conversion? Also, were you running headers or stock manifolds? I couldn't tell from the pictures. I'm looking hard into a 5.7 swap with TTI's, but there's no definitive answers on their website about the stock Z bar with the new hemi headers.

Gdemon is running a hays clutch if I am correct... and has 5.7 car manifolds on his set up..check the header fail thread, he has a few pics there.

Right i have been using centerforce for 10 years and had that same pressure plate in my demon for 5 years and never had a problem with it until i put it behind the hemi. I think the machine shop guy is right that the hemi's rotating assembly is alot lighter then the old motors and it is much more sensitive. All I know its like a whole different car with the hays in there.

pretty intresting,,ide like to know the real problem or why a canter force wouldnt work behind the 5.7, just sounds strange

The Hemi rotating assembly is very light and internally balanced so any outside influence will make it shake its brains out.

I may have read this in another thread but can't remember, what clutch setup are you using GDemon? Did you manage to keep the stock mechanical linkage or did you do a hydraulic conversion? Also, were you running headers or stock manifolds? I couldn't tell from the pictures. I'm looking hard into a 5.7 swap with TTI's, but there's no definitive answers on their website about the stock Z bar with the new hemi headers.


Yes im using stock linkage. With 5.7 LX manifolds

Cool, thanks for the picture. I'm holding out hope I'll be able to keep mine with headers for the time being. I read up a bunch on here about hydraulic conversions that people have done, but I'm not really sold any way yet. I hate to chop up my firewall too much and have seen several people go through a few iterations before they were happy with theirs.

gdemon you always have some great pictures of detail. did you ever post a build thread?

So GDemon, since you're pretty much using all the same pieces I want to use, what starter did you end up using? I read about a bunch of different mini starters that are supposed to work, but I didn't know if that was purely for header and exhaust clearance or a block clearance deal. I've heard some people say they had to trim the block a little to make a starter fit, didn't know if I could use the old one of my 318 if I ran the stock LX manifolds. Also, I read in another thread where you mentioned modifying the right frame rail for the exhaust manifold. What exactly did you have to do and do you happen to have a picture of it? Looking like with any luck I'll be trying to put the 5.7 in my car next weekend if the parts show up.

Yes I had to grind the block a little for the starter clearance.I dont have a pic of what it looks like after but i have a before pic. I ground the two bosses above the oil pan on a 45 deg angle. The starter was just touching the top of the boss.On the starter itself i used a mini starter from a 90's dakota. On the frame rail is was kind of a scalop. Ill add a couple of pics.

Okay, thanks. I see what you mean about the block bosses. Figured it would probably be easier to just bite the bullet and get a starter now and try to fit it with the engine on the stand and not while in the car. The frame rail might be interesting for me though. I only have a little 90 amp flux wire mig welder with a spotty feeder and no real training, lol. Don't suppose that's something I could do with a hammer and 2x4?

Map63vette, You would be surprised about the frame rail. They are not that thick and a 90 amp mig will do a good job. If the feed on it is not smooth it is most likely just the liner in the gun. Depending on what welder you have the liner may just be replaceable. If it is permanent then blow it out with some air and run some wd40 through it. You would be surprised at how much that will help.
GD thanks for the pics. I may copy the frame massage instead of trying to track down some Jeep manifolds.

you guys are sure that with some frame notching the stock LX manifolds do fit? Really? Both sides?

ooops, I have 6.1 manifolds..

Yeah, I figured it might be enough to weld it. I modified the rear suspension on my car with it (welded a lower shock mount on an F body setup) that's held up okay. I just have zero training in welding and am pretty much just flying by the seat of my pants. Finding out that the feed was screwing up helped a lot in making cleaner beads, but the flux wire still has a bunch of spatter. Just didn't know how much I wanted to trust myself on a frame rail.

Yeah, I figured it might be enough to weld it. I modified the rear suspension on my car with it (welded a lower shock mount on an F body setup) that's held up okay. I just have zero training in welding and am pretty much just flying by the seat of my pants. Finding out that the feed was screwing up helped a lot in making cleaner beads, but the flux wire still has a bunch of spatter. Just didn't know how much I wanted to trust myself on a frame rail.

Check out the local vocational school, they usually run night classes in welding and it is usually pretty cheap.

you guys are sure that with some frame notching the stock LX manifolds do fit? Really? Both sides?

ooops, I have 6.1 manifolds..

I have a new set of 5.7's I'll trade you for the 6.1's