matejcekautoworks

hey guys i have a 91 cherokee laredo, with the 4.0 and auto, the engine needs to be replace and i have a 4.0 sitting around from and 88, will this engine fit together with my tranny? and what other stuff do i have to do to make it works with my jeep, thx guys

Dillon470

im 90% sure it will but you might want to wait for some more people to post

LimitedXJAddict

Everything that I've looked up leads me to believe that the two should bolt right up. I do know that the blocks are the same between the non-HO and HO, or at least thats what I've been told. The 91 should be a HO, and has a different fuel injector system and you'll probably have to change the fuel lines, wiring harness, computer, etc. Though if your 91 head is fine I'd just pull that and slap it on the other block... quick check removing the valve covers to compare bolt locations would confirm or deny this... I've got a 90 and 92, but don't feel like pulling the valve cover to check :P

jeepfreak82

I have a 94 and my friend has an 89... Not sure but I don't think that the head will interchange... The block as a basic part is the same where it meets the tranny so that will be the same. The 91 depending on prod date should be an H.O. like addict says so there may be minor differences in the head itself but you still shouldn't have a problem. Only other thing that I can really think of is that the fuel supply lines and return lines are different on the older motor

LimitedXJAddict

Just asked my mechanic brother, the heads do interchange between non HO and HO motors...

jeepfreak82

Ok, like I said, wasn't sure, but I do know the rest of the block itself is the same. May want to use your head to make the swap easier

BlueXJ

Block will fit just fine the head and the injection systems are different. The head will work but the intake and exhaust ports are slightly different. The later head can be made to work with the earlier block as the bolt pattern is the same so retain your 91 head and slip the 88 block under it and bolt everything together.
What is wrong with the 91s engine? Can it be used after a ring and bearing exchange. It can become the basis for a stroker if it is not cracked or a hole blown in it.

matejcekautoworks

ok kool guys, i lvoe this site now lol. i looked really close at the stuff, looks like the AC pump is different, and the alternator and the powersteering pump, but all that can be changed very easily it looks like, i already got all the front stuff taken off the 91 and i did pull the valve cover and it all looks to match, so i'll just swap the heads insted of doing all that other fun stuff. the p.o. ran it out of oil, so it knocks something terrable, i haven't pulled the head or pan to see wut im working with but i have never had an engine knock so bad, what company is the best to go with on a stroker for these engines, what about body panels, like the rockers, i figure im putting in all this time on the engine i might as well make it look good too. thx guys sorry for the long winded reply, ya'll are a great help