lild

I'm new to the forum world and the jeep world but I have 1998 jeep cherokee with a 3.5 inch pro-comp lift and 32 inch tiers I just blew a head gasket and I'm thinking about putting some money into it while I have it torn down. I just wanna do a cam some head work the newer intake and header. And suggestions on the parts or different mods would be appreciated.

brendancfarrell

What head are you doing? Also, are you a split header right now or 1 piece.

lild

I saw a conversion kit to run the 4.0 H.O. head I was thinking about that and right now it's a 1 piece original manifold. I want a single out header

Fred/N0AZZ

If you have a 98 you have an HO motor already.

lild

Lol see new to the jeep thing. Any idea what I could do to the head or will valve springs and a port and polish be good enogh?

Big David

I had a 98, I put a 99 up intake, 784 Neon injectors, & Ebay aftermarket header on. I could tell a difference in the performance. Around $200 for it all.
I do think it was getting better mpg too.

brendancfarrell

Throw a 0631 on there, run a 99 intake manifold and header. Obviously get the head checked out by a reputable machinist and get it cleaned. Clean up the valves and springs and install. Just make sure everything you take out and reuse, is labeled when removed and put back Exactly the way they came out. If you want power, stroke it.

lild

0631 that's the casting number on the head right? Is that really better then the H.O. head? And from what I hear if you put a cam in you gotta get stiffer valve spring so they don't float.

bryweb

Not worth the effort to swap out in my opinion

From the link below;

"Head Games
Myth: The '91-'95 7120 casting number are hands-down the best power producers, followed by the '96-'98 0630 and then the '99-up 0331s. The early heads have far superior flow numbers and resist cracking better than the later heads and will make way more power.
Our Thoughts: We don't argue the flow numbers of the '91-'95s are the best, but the later-model HO head flow numbers are generally within 10cfm at the crucial mid-lift areas. Given the conservative factory camshafts, that 10cfm isn't going to do much. All 4.0L heads feature only moderate flow numbers for performance, but offer high-velocity, which is good for low-mid rpm torque. And any '91-up HO head will absolutely kill any '87-'90 non-HO head.
Claimed Gains: 30hp
Actual Gains: 5-10hp
Notes: With the relatively small duration, low-lift factory camshafts there's not much need for cylinder heads with huge flow numbers. The factory heads are well matched to the factory components. It's only when increasing camshaft duration and lift profiles that aftermarket aluminum or ported 7120 heads show their true advantage."

http://www.fourwheeler.com/how-to/en...ing-true-lies/

lild

Ok so I'll just put the stiffer springs in the head. Other ideas for the cam, header, or anything else

93XJeeper

I've go the 91-95 head and my jeep is pretty fast compared to the others I've driven. Raced my friend in his BMW and almost beat him. Lol

lild

Any idea of a good cam to run?

brendancfarrell

I only said that because the 0331 head cracks. I've personally never seen one not crack. 0630s were much better in my opinion. I swapped a 7120 into a 01 cherokee and it required some modification to fit and seal properly, but that's because he had the split header.

lild

Now from what I can tell the head I have is a good one not the one that cracks. I'm gonna buy a comp cam kit with cam, lifters, and stiffer springs and use my old head just port and polish it.

MightyMouse8

Has any one ever installed a performance cylinder head? like the one that Clearwater sells?
http://www.cylinder-heads.com/cylind...yl-fits-91-07/