I plan to buy a hemi around Christmas for my truck. It's an 05 2wd 4.7 Auto. I've been doing some research, and it seems the easiest swap is to an 05 hemi (non Mds). But I've seen several good 08 mds engines for a good deal. So, what do y'all think is the easiest option for me? I don't mind waiting on it

 

I don't have experience with this myself, but i've read many forums about the hemi swap. FrenicX is really the pro at this as he's done it on his truck. I myself would love to get a 3.6 pentastar from a wrangler and drop it into mine.

Back to your hemi swap question.
Are you getting the computer with it or keeping the computer from your 4.7? if keeping the 4.7 computer, the 08 MDS hemi will will run but the MDS will not do anything. you'll be on all 8 cylinders all the time. And i'm not 100% certain, but i believe someone said that the hemi will not perform as well on the 4.7 computer, but like i said, it will still run. if getting the computer with it you will need to get the computer flashed with your VIN and a few other things. FrenicX is on every few days or so. Once FrenicX chimes in on this you'll have your full answers.

 

I don't really care for the mds. It's going to be a street/strip truck anyway, and I'm putting several performance valvetrain parts into it. Don't know if the lifters could take it. It depends on how hard the computer swap is to do, if it's a matter of plugging in a few things sure. I've been reading up when I can and it sounds like a feasible swap

 

here is the thread FrenicX made for his swap, tons of info in there that you can use

https://dodgeforum.com/forum/3rd-gen...-1yr-plan.html

 

Honestly it's a very easy swap. I say make sure to get a dyno tune once you get your mods settled... I have never been able to get the idle down very well with email tunes. I started developing a misfire on cylinder 3 and I'm worried about compression.. hopefully it's just the injector.

If I could do it again, I'd go with a LX motor from a magnum/charger/challenger.. NON-VVT. I really should have gotten a 6.1 when they were cheaper, even higher miles. These Hemis are really reliable and I was a fool to think I "needed" a 0 mile engine.

The difference is the intake manifold, throttle body position, timing cover, exhaust manifolds, and accessory position. Other than that, a LX car actually weighs in at around the same as my lightened truck, give or two a 100lbs or so... heavy *** cars.

the benefit of having an LX motor, is that they drag the power a bit further through the RPM range, and you can get simple upgrades easy, like heads and intakes.

If I could start over, I'd get a 2005 lower miles hemi from a car, a Spartan cam, 09+ (eagle) 5.7 heads, 09+ eagle intake manifold (needs runner adaptors), and the BRAND NEW 90mm BBK throttle body. They have 80mm, 85, and 90. When I started my swap, they just had the 80mm and I had it bored out by Rich at HiPoTek.. a true 84mm bore, with new restrictor plate.. not just a gaping port job.

As for tuning.. there's no doubt that the Ram PCM will give you more options.. but I'm fairly confident a dyno tune with SCT will be just as good. Switching to a Ram PCM is still a bit of a mystery to us... The truck will run with a 4.7 Ram PCM, but the entire dash is lit up with dummy lights.. There might be more than can be done on the tuning side of things to make it work without a full rewiring of the pin-outs, but for now that's what we have come up with. I will be getting a dyno tune on the truck finally after Christmas and I will let everyone know how it goes.

 

I should have updated this earlier I guess. I ended buying a 2005 hemi out of a 2500 truck. Complete engine for $300. I was skeptical naturally, but now that it's in pieces in my garage it looks really good. Still going to be machined .0030 over, decked, honed, and so on. I'm hoping to get 450 crank hp. (Heads, cam, intake, exhaust, tune). But it will be a long process as I don't make tons of money (I'm still in high school) but I'm staying committed. Trying to gather all of the information I can

 

Since you have it apart, it's certainly not too late to upgrade.

The heads on the original 5.7 aren't that great. Even after P/P. Stock 5.7 eagle heads flow better than P/P 03-08 heads, and almost as good as 6.1 P/P heads. So imagine p/p 5.7 heads..

With an apache or eagle intake manifold it will be a screamer..but you'd need a car timing cover, or the machined truck timing cover from inertiamotorsports.com

Headers are hard, any long tubes would need extensive modification and most shorties will need a small mod of some kind. 6.1 headers aren't even close to fitting. That's why I went with gibson logs. I don't know how well they are working, I have thought of switching to stock manifolds for flow.

Other than all that, my thread mentioned above has a lot of the info you need. But I'll definitely try to answer any questions. I'm more reachable on Facebook, my name is Preston Elmer if you need anything.

 

AND dont for get brass soft plug while the engine is out. and anti-sieze compound on ALL threads on the bottom. AND the ext bolt threads. on the ext manifold tighten the bolts to 70-80 % of full torque first. then after 4-6 full heat cycles take to full torque. more anti-sieze compound on threads.

 

Good info. Really looking for any help I can get with this project. I'll probably create a new thread when I get the block to the machine shop

 

Just out of curiosity, what region of the country are you in?

Also, I might be selling my 84mm cable operated throttle body, just the part you'll need to get air into that hemi. Bored out by Richard at HiPoTeK. I'm contemplating a new 90mm one I found out about. 90mm is overkill for my current setup, but I don't plan to keep my current setup for long. I paid $350 for it, and had it bored for $150. A new 80mm is $368 from bbk, or $500 from mopar performance.