I'm about to do a rebuild on my buddies 258 engine, my question is; have the 258 cranks changed over the years? I will be using his crank as a core for the machine shop and I want to make sure we get one back that will work.

there is an older one from the 70's that has larger counter whieghts. I am using this one on my Stroker rebuild. However I have heard of people using this and having problms with manual transmissions

The 1975 to 1980 4.2 crankshafts with the casting # 3214723
is the one with the heavy counterweights and is much preferable for wheeling.

scottv: What sort of problems were they having with the manual tranny? Has the pilot bearing changed over the years?
Thanks

yeah i'd like to know what the problem is to?

Well, I've been running my 4.7L stroker + AX-15 for about 3 years with no problems :) . 2 trips to Moab & countless trips to the Rubicon. The only part that didn't line up was the pilot bearing. Just had to cross reference the I.D. and O.D. measurements to find the right one. Good Luck.

thats an easy one,, pilot bearing for an ax15 is pn#53009180AB: 13.21 Engine Tech 818-999-3451 Richard

Whichever crankshaft you get back (turning yours in, getting someone else's back, right?), make sure the threads that attach the flywheel to the crank are good before you do much else. They are nototioous for stripping on the 4.2 cranks.

There's also a long snout/short snout variation in the later ones (short = serp belt).

You can grind down a long one to properly locate the serp balancer, or use a spacer to move the balancer back on the long snout.

The issue I had with the pilot bearing was the O.D. of my AX-15, I replaced my 90 tranny with one from a 95 = different size? The snout on my crank was too long for the ballancer bolt/washer to tighten down on the pully, but a little time with the grinder and I ground the snout to the proper length and it's been good ever sence.