Not a hard fix. I replaced my head with a TUPY head from a 2004 grand cherokee. The tupy head is the heavy duty casting my Jeep. In total I spent around $70 for the head from a salvage yard and another $120 on all of the gaskets for the head, exhaust, intake, throttle body, valve cover, and thermostat housing.

Well I think I'm gonna buy a promaxx performance cylinder head and well I'm taking stuff off and putting things on I think nows a good time to add a board throttle body and spacer as well as a new air intake

If you haven't bought the spacer yet, don't. Spacers add nothing to the 4.0 or any M.P.I. motor for that matter. Bored throttle body is a good idea as well as an injector upgrade while you're there, pretty sure your Heep will take the 784's.

Ok I'll skip on the spacer and recommendations on which throttle body to get? I'll have to look into the injector upgrade as well

look no further. I bore throttle bodies and usually sell rebuilt injectors. I also make battery cables if you ever go down that route.

I'll have to look into that as I get closer to doing that. its going to a buddy's house this weekend to have the head swapped out and then I'll have to wait and see what else I'm gonna be doing well its over there. I got my 96 back and I'm gonna start driving that for a little bit.

ordered a few more parts for the 2000 should be arriving here in the next few days then I should be able to get it back on the road again here really soon. going to go with a 4.5'' lift kit as well as 32'' inch tire and trim the fenders. I'm thinking about ordering a set of the notch customs fender flares and as well as some new rims will see.

Did you end up installing the Promaxx head?
If so, would you buy it again? I am in the same spot you were in. Any reviews would be very helpful.
Thanks.

no I didn't I need to get the Cherokee back on the road so I ended in getting a tupy head off ebay for a little better deal and I'm gonna run that for now but I'm gonna start getting stuff together for a newer backup motor probably like a 4.7 L not sure yet but this head seems to be doing good for now I'm gonna do the injector upgrade as well as an air intake and a bored throttle body. I have read a lot about the promaxx head and it seems to be really good and if the timing would be a little bit better I would have got it.

well its been a while since i posted anything in this forum i had to get rid of project new life cause we had another baby and need to make room for another newer vehicle that would better accommodate the family. i haven't been able to make as much progress as i like on the dd that my wife has dubbed the beast but i have been picking up bits and pieces here and there as i can. i ended up picking up a set of mobi wheels and a Olympic top hat roof rack for cheap. i also picked up a set of jcr rock sliders from my uncle that he decided he wasn't going to use. i have had to replace the water pump and thermostat housing as well as the hoses and the radiator. i did the hubs front brakes and rotors as well as the shocks. i picked up a set of the jks acos adjustable coil-overs to help level out the front and plan for many more things to come.