You dont have to change the crank, I have a partial write up of my swap on another site, I forgot how much better this site than the ones im on lol, but if you need just ask. Hope this helps.
What I put in it, A 1996 Pathfinder 3.3 V6 with around 55,000 miles on it.
I have the 96 motor powered by an xterra setup
I used the alternator, powersteering pump harmonic balancer, oil filter housing all from a 2002 xterra.
For wiring I used a 96 or 97 wiring harness I got from the Junk yard, then spliced it to my old harness. I know I know.. I need to put up pictures!
I used the original motor mounts and exhaust manifolds.
I also used the new 3.3 intake on it
For the radiator I ran the 96 set up to the old set up which turned out nicely.
I completly got rid of the AC, I didnt really use it anyways...
I have the manual tranny and I used the 96 clutch with it and it all matched up.
Along the way I replaced tons of other parts, this is just a quick write up of what I did, I will make a full write up another day
I did some ecu test on it and it has NO CODES!! ALL SYSTEMS GO!!!