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View Full Version : 258 heads on a 4.0 HO



jeep-freak92
07-05-2012, 11:57 PM
im wondering if anyone has put the 258 heads on a 4.0 High output and if anyone know if it lines up or what kind of mods id need to do. I looked online but all im seeing is posts about putting the 4.o heads on the 258 motor. I've got a bad valve ticking noise and id like to just replace everything plus id be getting the new to me heads for free so that also makes it attractive.

i know that people use the 258 cranks to make strokers so im assuming the heads on that motor would have more clearance than the stock 4.0 ones would this effect anything.

Thank you in advance for the help.

Also if i was to just us the stock head and do the valve train work does it sound ok to just do lifters rockers and push rods? when the valve cover was off i started it and some of the push rods were spinning while the vehicle ran im assuming thats were some of the noise came from would you recommend doing more or less or does that sound good?

highlandercj-7
07-06-2012, 08:00 AM
That's shooting yourself in the foot. Most folks put 4.0L heads on 258's, it's said they flow better. The only thing used in a stroker 4.0L is the 258 crank and rods. Also IDK why folks put 4.0L heads and FI on a 258, your better off using the whole 4.0L. After all the work the 258 is still less HP than the stock 4.0L.

joe_and_jeep
07-06-2012, 08:05 AM
Theres a reason people put 4.0 heads on 258s, and there is a reason no one puts the 258 head on a 4.0. Unless you have a burnt valve or a cracked head the 4.0 head is fine and the noise is in the lifters. I would try running a good engine flush, changing the oil and adding a additive. I like Lucas. Maybe your lifter will pump up.

HeepH8erTy
07-06-2012, 10:30 AM
That's shooting yourself in the foot. Most folks put 4.0L heads on 258's, it's said they flow better. The only thing used in a stroker 4.0L is the 258 crank and rods. Also IDK why folks put 4.0L heads and FI on a 258, your better off using the whole 4.0L. After all the work the 258 is still less HP than the stock 4.0L.

ive heard people talk about doin the stroker 4.0's but never looked into it. Is that literally all you gotta do is swap the crank and rods? what does it bump the displacement to? 4.6?

PatF10
07-06-2012, 10:48 AM
no the 258 head will not work. While it will bolt on, you dont have the correct waterjackets going through the head and block. Plus the intake runners on the 258 are lower and your manifolds wont line up on the older head. Find a decent 4.0 head for a replacement and save yourself a big headache.

jeep-freak92
07-06-2012, 04:47 PM
alright i wont be puting on the 258 head... this means ill be doing valve work on the head i have do you recommend doing anything besides rockers lifters and push rods for the ticking noise?

Also i did change my oil and add sea foam to the new oil but it doesnt seem to be helping.

5 SPD XJs
07-06-2012, 05:56 PM
There is one in the for sale section $50

gonecheenin
07-09-2012, 06:27 PM
I got one off of a 90,000 mile ZJ 4.0 I'd sell for $100

alex211
07-22-2012, 02:11 PM
I would never do that, the 4.0 in my rubi is a pig. Any less power would put me in 4 banger territory.

Stroker 4.0s are built with a 258 crank and rods, then someone makes pistons with the correct wristpin height to utilize the 258 rods. I'm like 90 percent on that.