Head swap

[jimoshel]

Would there be any thing to be gained, performance wise, to justify swapping a 2000 Grand Cherokee head with a 1988MJ? 4.0L.

[Geonovast]

The head is supposed to be a better flowing design, however, the intake ports won't line up correctly with a Renix manifold, and an 00 should have the 0331 head that has a reputation for cracking. The 00 head also would not have the hole in the back drilled for the temp gauge sensor. Unless there's something wrong with the 88's head, I'd leave it.

[ratrapp]

i did the head swap using a 93 head and 99-up intake.aside from fixing the oil leaking head gasket i seen no improvement in power or fuel economy.i do need to change my exhaust manifold to a ho style but i can't see it holding it back that much.i wasted a couple hundred dollars on the swap.maybe my shortblock is that worn out but i wouldn't waste my time doing it either.

[dakineJ]

i did the head swap using a 93 head and 99-up intake.aside from fixing the oil leaking head gasket i seen no improvement in power or fuel economy.i do need to change my exhaust manifold to a ho style but i can't see it holding it back that much.i wasted a couple hundred dollars on the swap.maybe my shortblock is that worn out but i wouldn't waste my time doing it either.

Which throttle body, fuel rail, and injectors are you using? Did you gasket match the intake to the head? An APN header would be a good,inexpensive replacement for the oem ... then there's the Magnaflow highflow cat/muffler/2.5" tubing,etc. on and on haha.

[JeepcoMJ]

use a '91-'95 fuel rail, injectors, and throttle body.

 

 

the throttle body can be spliced in to work.

[jimoshel]

I got a kid comes around sometimes interested in mechanics. I used that head to teach him how to do a valve job. Then milled the mating surface to clean it up. It's just sitting on the shelf and I just wanted to see if I could get some use out of it. No big deal. Anyway appreciate the comments. Jim

[kro10000]

Agreed, stay AWAY from the 0331 heads... especially the early ones (99-02) if you were to do it youd want to use a 0680 (IIRC)

[ratrapp]

i did use the 91-up fuel lines and tb.i bought the hesco tps adapter to reuse my stock renix tps.i had already replaced the injectors with the four hole pintle style awhile back.i had already put a high flow catco converter and 2 1/2 exhaust with a 2 chamber flowmaster on last year.i am going to replace the exhaust manifold and down pipe soon and see if it's really holding it back any.