4.0 head

[Dan77CJ7]

Hi guys, I'v been wanting to do the 4.0 head swap. i'm not going to do a cam, just want a little more....then i'll be happy! want i need to know is what year to look for and how i need to rebuild it, and what mods i might need if any? my current intake is off a 79 AMC concord.. i was told to use the 98 "barrel type" intake off the GC. thanks.

 

[hole]

Your looking for a head from 91-95 casting #7120. Personally I didn't like the idea of closing the water jackets with packing peanuts and JB weld, so I got a remaned head from Clearwater. They weld the jackets up and then surface the head.Shipped to my door $450

 

[ThisGuyUKnow]

Your best bet and bang for your buck is to buy a rebuilt head online. There are plenty available on eBay.You'll end up sending about the same amount of money as if you went to the junkyard then had a shop rebuild it.

 

[gutthans]

Allow me to add some corrections to the previous posts:

2 heads are preferred: #7120 and #0331. DO NOT USE #0630

You DO NOT ALWAYS need to fill the triangular ports on the new head. IF you have a '87 - '90 AMC 258 i6 / 4.2l it is very likely the head will install with no problem and without filling the ports. The AMC 258 i6 / 4.2l block core shift often placed the ports too near the edge on early blocks, not so much the Wrangler years. Eyeball the assembly, or (better) lay a 1/16th composition or cork sheet onto the head and mock install the head. The raised impression will reveal if the ports are too close to the edge.

Pay careful attention to pushrod preload.

http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf

You'll want .020 - .060 as a setting on the new valvetrain. 9.625 is the accepted stock length, but note that a full Sealed Power box will vary about
.025 from the shortest to the longest in the box.