PDA

View Full Version : 258/ 4.0 parts sharing - what fits?


Cheropair
April 25th, 2003, 20:34
Just picked up a '80s something 258 from a CJ, wanting to use it with '87 4.0 to make budget stroker.

As I disassemble the 258, just wanted to know what parts interchange, i.e. -
waterpump
rockers
pushrods
lifters
head
oilpan
brackets (OBA?)

Need to know what parts may be kept as back-ups for future use!
TIA, Cheropair NAXJA #449

Eagle
April 25th, 2003, 21:01
If the 258 had conventional vee belts rather than a serpentine belt, the water pump rotated in the opposite direction and cannot be used with the 4.0L block and serpentine belt setup.

I believe the block (deck) height for the 258 is different than the 4.0L and therefore the valve pushrods may not match up. Measure them carefully against the 4.0L pushrods.

Lifters should be interchangeable, but again -- check length.

I doubt the oil pan is the same. Might bolt up, but I'd bet the old CJ used the AMC-standard 5-quart oil pan, which will not be compatible with the 4.0L oil pump pickup.

If it were mine, I would keep the crank and rods and toss everything else.