rods, crank, and procedure questions

[Electric Stooge]

ok, so here is my issue that im fixing. I got a tick and I believe its rod slap due to the last time I had the pan off and one of the rods moved on me.
So im planning for the worst here and seeing what parts Ill need to do a bottem end stroker because i dont see a point in just returning it to stock.

so here is my questions
1. could i just replace that rod and put in a 4.2 crank shaft?
2. can i do all this from the bottom with out removing the head?
3. would this actually give me a power gain
4. if I only wheel once a month and i do still try to get decent gas milage out of it, should i find a 4cw or 12cw crank?

current engine is a jasper 243 rebult thats out of warentee in a 00' xj auto
Thanks in advance

[Cheromaniac]

At a minimum you're going to need a 258 crank with new rod/main bearings for the HO block. The question thereafter is how to complete the stroker bottom end. You could either keep your existing 4.0L rods and add a set of IC944 pistons, or buy a set of 258 rods with some cheap stock replacement pistons. Either way, the rod big ends will need to be checked for roundness and a set of ARP 112-6001 rod bolts will be good insurance.
With the stroker bottom end complete with reused stock cam, you could just bolt your existing cylinder head assembly onto it.

[Electric Stooge]

yeah, i wasn't going to change cams, and If i need to take the head off, I would minimum check the valves were seating properly.

but from what your saying, I couldnt use the 4.2 crank with both the 4.0 rods and pistions, i would have to change out one of them?

[SilverXJ]

Correct. The 258 crank needs to be used with the 258 Rods & 4.0L pistons OR 4.0L rods and Icon, Bulltear or other custom pisotns

[Electric Stooge]

oh, dont know how I missed that in research.....
That probally would have ended in a bad mistake, so thanks!

[Cheromaniac]

oh, dont know how I missed that in research.....
That probally would have ended in a bad mistake, so thanks!

You wouldn't have missed it if you'd read this page:

http://www.jeep4.0performance.4mg.com/stroker.html