Hello everyone. So my 2008 has many issues with the typical engine and wiring and everything. New intake, injectors, throttle body, harnesses and pcm to say the least. Still having issues with everything and I am a little tired. So I have been throwing around the idea of an engine and transmission swap for it. After carefully reviewing the usual suspects I narrowed it down to the 5.3 lm7 I have laying around in my father’s house or a 5.7 vortec. I only have the 5.3 engine but no accessories and no pcm. Now, I do have a complete 2000 chevy ck2500 that has the 350ci 4bolt main vortec in it and mateted to a 4L80e with only 100k mi. That is a truck I had bought at auction many years ago but could never get it titled. That engine purrs like a kitten. The truck was a fleet truck but rarely used in a university campus. Since the truck only came with bare bones and my wrangler x is also bare bones I imagine that it should be even better for the swap. I have been trying to find anything on this specific swap but all I find is for the LS. There is a thread that got started on one of these swaps here but nothing much after about 5 posts. I messaged him to see if he ever finished the build and for any information he might have that could help me so I have to wait on that one. But if there is anyone who can point me in the right direction or has done the sbc350 swap and can share some imput it will be greatly appreciated. I know I need the engine mounts and have found some kits for the transmission mount and adapter for my tc. I know my exhaust system has to change and I am aware of all the misc things that go with it. I have done crazy things with my old friend and I am also a decent fabricator(not aerospace good but good) so ALL good vives and help will be appreciated and hopefully I can start on this soon. You can see my jeep in the newbie section. Yeah, the white RHD ex mail carrier😂😂😂😂 Thanks guys and have a wonderful day!!!!

 

These things are big trouble trying to get a ECU controlled different engine into them and mating that ECU to yours. I used Motech LS Wrangler in Las Vegas and got the system adapter for LT Chev from Robbie. It basically makes the entire Jeep,integrate with the engine. A guy here put an LS into a Jeep on a budget but he bastardized all the electronics speedo tach etc to work. Me? Mine is like the factory unit as if it came with a V8 but it costs - a lot. 4 years now and never left on the side of the road or the trail.
For starters a SWB JK will have a super short driveshaft that may eat U-joints as the TCase moves back a few inches so you need 2 driveshafts but I am talking the 8 speed 8L90 tranny when talking about length. I know this sounds weird but if I did it again I would modify the 3.8 as it is a stout engine when you put the caravan connecting rods in and aftermarket pistons. Forged pistons, higher compression, good torquey cam, bigger injectors, cast iron exhaust manifolds and slight port and valve area clean up with ECU remap. Would give you an honest 275HP and pretty good torque. Don't use the Jeep rods or pistons they are garbage. The basic block, valvegear and oiling is pretty good right out of the box. Failing that if you want a V8 get your hands on a 5.7 or 6.1 Hemi early model with 4x4 truck tranny (it has the low 1st gear) as your stock ECU has both those engines as a choice on the menu. Still a lot of programming to do though. No easy route nowadays or you could go back to a CJ7 and spend a weekend putting a carbed SB Chev in there. With CJ's though the 360 & 390 Javelin's fit straight in if you have a 304 unit.

 

Thank you for the information. I am still in the thinking process of what to do. I do have all these parts but at the same time I really would like to not have to do all this and just go and rebuild. I am not shy to do it, just cost effectiveness and time. It is not my DD so that is a plus. Maybe I can sell the other truck and get some cash to throw in the jeep….. let’s see how that turns out. Thank you and if you have any suggestions for me please share them. I will definitely try to do the best for what I need.☺️☺️🙏🏼🙏🏼🙏🏼

 

Since you already have that donor truck from the used cars for sale in usa https://carfast.express/en/auction auctions, it makes a lot of sense to use what you have instead of buying more LS parts. The RHD setup is going to be the biggest pain with the steering shaft clearance, but if you're a decent fabricator, you can probably notch or relocate things to fit that old school 350 Vortec. I’d say go for it, wiring the gauges to work is a headache, but having that 4L80e reliability in a JK is a massive upgrade over the stock setup.

 

Yes. That is exactly what I was thinking about. Looking at the steering shaft it is a tight place. Will have to measure. Thanks you!!!!

 

Out of curiosity (as the worlds premier mediocre 2008 jk enjoyer) id be very interested to hear specifically about the problems you’ve and the steps you’ve taken to diagnose the issue(s). It sounds rather extreme to swap the engine out after buying almost all the big ticket items (assuming you mean upper intake plenum, all 6 Mopar injectors, throttle body. I always feel like an ass attacking people when I ask this kind of question, but I must know the details if I’m ever going to finish my 1000+ page phd thesis.

 

I’ve experienced my fair share of electrical problems with my 08 3.8. 2 helpful bits; replace battery cables, cycle the key quickly 10 times. 1 thing I stumbled on the key trick by accident. It puts your computer into a learning mode and clears codes. I had done hydro assist, speed sensors, cam shaft sensor, ran in through JScan module resets (and my tuner resets) and just about every light was still on my dash. I had to get a new key and it wasn’t cut perfectly so I cycled it about 10 times to break it in. Since then zero abs, bas, brake light, and some codes went away (been over a month) Then a couple sensor codes came up, I swapped out my battery cables with the Jeepcables kit and my gremlins are gone. Just my pesky egr issues left.

 

Awesome. I will look into it. Haven’t had any time to do so because of things I have to get done and since it isn’t my daily driver I can take my time. My cylinder 3 misfire is the worst. Pulled the plug and it was wet with fuel. Cleaned, and cleared the code but still there. There is no leaks that I was able to detect with my tester or carb cleaner. Thinking maybe valves on that head….🤷🏻‍♂️ thanks for the replies. Will be getting to it soon because I want it running!!!