I may be looking for a replacement engine and was wondering what years are the best for the 4.0 straight 6 that will work in my 94 JGC.

Thanks,
Miles

 

I'd look for the early 4.0s (late 1980s to 1994) because they have 190 horsepower, whereas the later 4.0s from 1995-2004 have 185 horsepower. Good luck, they're easy to find (:

 

96 saw the thickening of the webs and the addition of the main bearing girdle.
2000 saw the addition of the 0331 cylinder head.

Therefore...
96-99

 

Where did you find this data?

 

Weird, all other info out there shows late model 4.0s having the bump in power.


And your year break up doesn't make sense.

 

Exactly

 

If I where you id go to a(u-pull it) junkyard and get a engine from a 96to99 but pull the cylinder head off and then find another one from 90-95(7120 casting) and pull that cylinder head off temporary put em together and pay for complete engine, its gonna be alot of work and might sound a little crazy but your going to have the best 4.0 combo!

 

Question, Gentlemen! What year was it they changed the motor mounts? Remember it's going into a 94.

 

You can not use 87 - 90 4.0 in a 94 as these are Renix engines. Use the engines as per the previous post, just remember 99 up 4.0 is where the mounts were changed.

 

Thank you

 

Thanks everyone, This is what I needed to know.

Miles