My 08 JKU is powered by the 3.8l factory motor. It has 120k miles and will eventually fail I'm sure. the rear main leaks and that will need replaced at some point also. I have been looking at rebuilt 3.8s as well as Hemi or LS swaps but they are all somewhat pricey! I own a small block Chevy motor with matching tranny and transfer case. My JK has factory power windows and locks. I am curious if it is possible to maintain these options without a factory wiring harness or if I could keep the computer and swap to carbureted motor. Not only would this drastically increase performance. But it would also solve a possible future problem for me. If anyone has any advice I would certainly appreciate it. Thanks in advance.

 

I want to swap to a cable throttle instead of a electronic one.

 

What year engine trans transfer case? Pre 87 I assume since carb. Those are passenger side drop tcases where as ours are drivers side. Power windows if they are controlled by cpu you should be able to bypass a new switch with relay to power off battery? I don't see alot of gain to be made unless you modding that engine well which is easy. Stock small blocks of that Gen where rated around 160 hp and 250-260 tq.

 

Wouldn't that also run into the minor legal issue of engine swaps having to be same year or newer?

 

I'm not 100% sure what year the motor is. It's already built and is mildly modified. 350+/- hp. I know there are other mods that would be needed. Shifter, drive shafts, etc. My bigger issue is cost and availability. I'm not opposed to replacing with factory motor when and if it's needed but Reman 3.8s are 2500-3000. And I'm sure you're aware of the hemi/ls prices. I have factory power options that wouldn't be easily converted to manual.

 

I doubt that I'll ever make this swap. I just wanted an option if needed. I would only consider it if my motor fails. My JKU is a daily driver so this would be a ton of work just for Shiz and giggles. Ha. But I truly appreciate your response. It leads to another question though. Is that a federal or state law? It makes total sense either way. I've often wondered if the vehicles have to get re-titled to reflect the new(upgraded) motor. I know that a lot of states tag the dash cluster to reflect mileage change over. Thank you again.

 

I assume it is Federal - but I haven't seen the legal code, it is just something that gets posted in every single motor swap thread. Might be worth an email to JSS or Motech or anyone else who does these swaps on a daily basis.

 

Makes sense for sure. It could become a street legal/inspection issue. I work in the wholesale auto industry and see rams and silverados in salvage sales regularly. Just haven't seen any jeeps yet. I suppose if ever necessary I could find my own Hemi. Do you know if its possible to use the new motor wiring harness? Or is it mandatory to buy the reprogrammed wiring? Also when swaps are made is there a conversion kit to use factory tranny?

 

Several companies make install kits to take all of the guess work out of it. They run somewhere over 5k, in addition to the engine/trans.

This is Motechs kit for the LS engine.
Basic Kit

And AEV makes one for the hemi
American Expedition Vehicles - Brute Kit, V8 HEMI, Aftermarket Jeep Conversions, Products, Wheels, Accessories and Highline Kits for Jeeps (TJ, JK, WK, XK).

 

Thanks man. Hopefully I never have to face that temptation. That's a lot of $$ to consider. But I'm sure the results are incredible.