Swapping 4.2 cranks question

I decided to refresh my 4.2 engine in my 420 since its out and the rear thrust washer looked not too good. Wanted to be sure the rest was ok.

My original crank looks pretty good, but needs a good polish. I have a early xj crank that is perfect. My question is can I swap cranks and use my original rods with it. I don’t see why not, but want to be sure.

What was/is your crankshaft end float, you may want to get an oversize thrust washer,
I believe its suppose to be 4-6 thou. The oversize is 4 thou bigger than standard size.
But anyhow I would definitely replace the one you are showing, what does the other one look like.

End float was fine. Just acidic oil ate material out. The rod and main jornals have the slightest fine scratches. I Can polish them out. They measure well within specs for std bearings.

But the XJ crank is perfect without a polish.

It’s always a good idea to remove the crank plugs, and then have it boiled out.



Whilst I’m not an expert but trying to answer your question I believe the crankshafts are interchangeable BUT I would compare them side by side and check the key ways for the damper, etc are in the same position. I think the flywheel connection is identical.
It is important/essential as has been said that whichever one you select that you remove the sludge trap plugs and clean the crank meticulously.

That, and remove the plugs with an impact and not with an allen key, then it is no problem.
Since you have both cranks I would just compare them side by side.