CJ5 Chevy Engine Swap

[Eric.Rogers]

Hey guys, I am a newbie here and even tho I have owned my 81 CJ5 for a long time I am still a newbie at all the conversion type stuff you can do with these things. With that said please excuse my naivete lol
So I am looking for advice on what Chevy engine to put into my CJ5. I know I want to go EFI. I do take it out in the woods and wheel it so torque is a major consideration. But I also want to be able to pull my boat to the lake/coast with it (which my current 258 4.2L 6 just won't do). It IS a daily driver for me as well. I am not too concerned with fuel economy (it's a toy, right? lol)
A few specs that may help: I already have the Chevy SM465 transmission mated up to my 258. I am running the old stock Dana 300 xfer case and the stock axles and gearing. I am running 33" tires.
Any and all comments will be VERY much appreciated!


Eric

 

[69jeepcj]

Hi eric, I have a 65chevy 327 in my cj5 with a car Muncie 4spd mated to a spicer18 tcase, so your conversion has been done many times, and has great aftermarket support. Im not very up on the more modern engines, so I couldn't tell you which one is better over another. Id go for a truck engine myself, as they were designed to work and haul, (torque). If you have the factory AMC20 rear axle you should at least get one piece axle shafts for it, the factory 2 piece design will not hold to the added power long IMO, and I have experience there. There are many here with far more knowledge on modern computer controlled engines than I, and am sure they will be along soon with more specific engine advise. happy jeepin

 

[Eric.Rogers]

Hi eric, I have a 65chevy 327 in my cj5 with a car Muncie 4spd mated to a spicer18 tcase, so your conversion has been done many times, and has great aftermarket support. Im not very up on the more modern engines, so I couldn't tell you which one is better over another. Id go for a truck engine myself, as they were designed to work and haul, (torque). If you have the factory AMC20 rear axle you should at least get one piece axle shafts for it, the factory 2 piece design will not hold to the added power long IMO, and I have experience there. There are many here with far more knowledge on modern computer controlled engines than I, and am sure they will be along soon with more specific engine advise. happy jeepin

Thank you sir. I DO have the solid axle kit. I did that after breaking the stock 2-piece axles 3 times lol

 

[Eric.Rogers]

An added note: My limited research thus far has me leaning towards the 2003-2005 4.3L V6. GM made quite a few nice modifications to that motor. 190-200 hp and 250-260 flbs torque. Are those good numbers for my CJ5?

 

[69jeepcj]

Your current 258 should have 125hp, the AMC 304 had around 150hp. Going to 200hp would be a nice gain. I have not driven a jeep with the 4.3 but have talk with people that have and ones that own them. They say it is about the perfect engine for a jeep, compact with good power and torque. Very popular swap and would make a good choice.

 

[Eric.Rogers]

Sweet! Thank you!

 

[69jeepcj]

I think the AMC 360 had 175hp and should bolt right up to the rest of your drivetrain with no major mods. Not fuel injected though

 

[Bounty__Hunter]

I've got a '96 4.3L here just begging to go into a Jeep. I had the ECM flashed to run without the rear 2 o2 sensors and had the engine wiring harness modified to be a stand-alone harness. I can get you all the company information if you find a donor vehicle or buy a salvage engine and harness.

My plan was to use the stock auto transmission, the 4L60e. You have to provide a VSS signal so I had purchased the AA kit for use on the 4L60e tailshaft. GM had many passenger side t-cases you can use, just watch the overall drivetrain length in the short CJ5.

 

[69jeepcj]

sounds like a engine could be waiting for you. The ECM being flashed already is a big plus as I understand with out it, the engine light will always be on. The VSS signal I have read about also, don't remember what it did but it had to be done. These are the type of things needed to be done as I understand if you are going to use a modern computer engine.. This one already has it done!! Going non computer is much more simple, but you don't get that nice fuel injection.