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Hemi swap (gen3) or 360, 340?

Started by Purepony, June 22, 2021, 08:57:08 PM

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Purepony

Hi all

I got the challenger running and so far so good but I noticed it's leaking some oil from where the intake meets the timing cover and cylinder head gasket. I attached a pic, now I wasn't expecting much from this engine since it sat for 3- 4 years and the place that remain factored it really skipped and just put this thing together like a cheap suit.

The plan is to get at least 6 to 8 months out of it since I just added the a833 and it's fun to drive but being that it's now 2021 I'm hoping the market support on the Gen  3 hemi swap  is a lot better, more affordable and easier.

I'm torn between a 340 since I've always heard good things about them but they are the same price as a gen 3 hemi and I'm also thinking a 360 since it would be easier to drop in since I have a 360 now but when it's all said n done I'd like the new hemi for almost the same price.

I'm looking at hemis from totaled vehicles 25-60k miles with ecm and no trans

The questions.

Is there any kits that are plug n play on the harness, the engine brackets ?
How about the accessories like the power steering ? I don't carr much fo ac

Any ideas input ?

Swamp Donkey

Not sure if you like podcasts, but episode #34 of Talking Mopars has Blake from DIYHEMI on. It's about a 2.5 hour podcast. But a ton of your questions will be answered.   I'm also going to put a 3rd Gen Hemi in my car.   I'm just buying everything right now, so I can't say 100% what works for sure.
1973 Cuda. 340 4 speed.

HP2

What is your mechanical and electrical aptitude? Its my understanding a 3rd gen swap is not a plug and play arrangement like a 340 or 360 would be.

How are you planning on using the car? In a mild build, 360 is a big torque producer which will make it a pleasant driver. 340 really shine at higher rpms and are happier there than being lugged down.


anlauto

I think that installing a new Hemi will be a bit more involved obviously, but it's not terribly hard. They do sell a "plug & play" wiring kit.
https://www.rosevillemoparts.com/product/gen-iii-392-hemi-6-4-wiring-kit/  and they do sell a engine mounting kit.

but there is the fuel delivery system, exhaust system, cooling system to consider as well.  :dunno:
I've taught you everything you know....but I haven't taught you everything I know....
Check out my web site ....  Alan Gallant Automotive Restoration

Purepony

Well as far as my altitude I'd probably guess on a scale of 1-10 a 3-4 on a mopar. It was probably a 2 before but I did do an ls swap on my camaro that included fuel system, trans (from auto to manual), some of the wiring ( brother in law wired that car), some cutting etc.

But I'm a bit more intimidated on these mopars, I know working on a car should be working on a car but every time I work on a mopar I end up doing the job 2-3 times over but when I work on an ls or a small block Chevy or even big block I do it once abd it's done. Did my satellite water pump twice, did oil pan three times going on fourth, did my friends 396 water pump in 45 mins no issues, did timing cover front n rear on ls, intake, water pump, thermostat and exhaust gaskets no issues.

I'd like to be able to do a 5.7 keep the oda833 I have without cutting or welding




Purepony

That's what I'm hoping. That it's easier than it was back in like 2010.

I wouldn't even mind a nice small block that someone removed in good working order like a 340 or a 360 but they're almost the same price as a pre owned  hemi

Purepony

What about cylinder deactivation ? Is there a hemi without it ? Or does it have to be removed ?


74-5.7

Holley now has the Terminator X wiring harness and computer available for about $1300.00. It's what I'm going to go to.
I am now running a harness I built/ modded from a 2004 Dodge Durango and a factory computer reprogrammed by B and G performance. The factory mod stetup does fine but I want the tunability of the Holley system.

As has been mentioned DIY hemi I has a lot of good info. And Hotwire auto sells harnesses that run a factory computer.

The swap is not difficult in itself it's running down the information about integrating the wiring that is a pain.
Once you have that it really is not difficult.

Good luck with the decision if you have questions just keep asking.

Doug

Purepony

Is it possible to do without cutting anything ?

RacerX

Quote from: Purepony on June 23, 2021, 07:09:56 AM
What about cylinder deactivation ? Is there a hemi without it ? Or does it have to be removed ?

The high performance hemis generally do not have the cylinder deactivation (MDS).   The
aftermarket ECUs such as Holley Terminator X do not control it, and it is usually not desirable
in these retro-swaps anyway.

The MDS can be disabled by swapping out the MDS solenoids for the plastic plugs used on the
HP hemis, and changing the lifters to the non-MDS lifters from the same HP engines.    The cam
should be OK.  Some say you should change it for maximum benefit but leaving it won't hurt anything.


RacerX

Quote from: Purepony on June 23, 2021, 09:28:22 AM
Is it possible to do without cutting anything ?

Cutting depends largely on what transmission you use.   If you go with 727 or A833 4 speed,
no cutting required.   It will be the simplest to do, and require no external controls for the trans.

Later model transmissions may require some work, the amount of work generally increasing exponentially
with the "newness" of the trans model... 



Purepony

Yeah I'd plan to just go with the a833 that I have and call it a day. I was hoping someone sold a kit like they do with the ls swap that places them in the right position and clear accessories.

Any idea on the power steering pump ? Also headers or manifolds ?

Hmm it's just looking better and better to go that route

js27

There is a Facebook group Called Gen 3 Hemi Swap. I just posted the same question on there and got tons of info. I am thinging of doing a swap into my 67 Satellite. Since B-E bodies have about the same set up it should work for you also. Holly makes all the parts needed. K frame-oil pan-TTI headers-Fuel Tanks-Harness. From what I was told the 727 in my 318 now will bolt up no changes needed. If I wanted to run a newer trans then the tunnel will need to be cut and a new one fabricated. Stock oil pans will not work so you will need the one from Holly but I heard they are on back order. It is not as costly as some people think unless you go crazy. My friend told me he just put a 5.7 in his 95 Dodge pick up and did the whole thing for $1165.00.
Good Luck
JS27

74-5.7

TTI has mounts and headers. I Used TTI mounts and stock manifolds just depends on how much you want to spend. For power steering use a Pump from a 1989 Pontiac sunfire or that style with dodge pulley. Some say just use the stock modern hemi power steering pump and you will be ok.

RacerX

Quote from: Purepony on June 23, 2021, 12:41:39 PM
Yeah I'd plan to just go with the a833 that I have and call it a day. I was hoping someone sold a kit like they do with the ls swap that places them in the right position and clear accessories.

Any idea on the power steering pump ? Also headers or manifolds ?

Hmm it's just looking better and better to go that route

Some people report clearance problems using the original G3 hemi power steering pump, and also
it is said to have too much pressure for the older steering boxes.

Holley sells a power steering pump kit that includes the proper pulley and a pump that is already
modified for lower pressure/volume to suit the older power steering gears.    It is pricey, but solves
a few problems all at once.    It is based on the GM power steering pump mentioned by @74-5.7 so
in theory you could get one from autozone or rockauto and just buy the mounting bracket from Holley
for $50.   

For manifolds you are limited to those from a Jeep Commander or a Jeep Grand Cherokee.   I don't
like headers so my project will use the manifolds.

I've started a thread in the "modern hemi swaps" message area detailing my prep work for installing
the G3 hemi into my '71 'cuda....     a lot of this info will be there.

https://forum.e-bodies.org/modern-hemi-swaps/26/392-hemi-build/21382/