uhum... I have heard that the yukon diff has a bigger pinion, one of the main reasons for my worries is that I have to change to 4.88 from 5.71

I am currently running 5.71 4cyl. diffs. with an 2,4 turbo diesel interc. and 39,5 trxus. I am going for a 350 chevy and am thinking on going for 4.88 v6 and a high pinion front.  I am hoping that the 4.88 v6 is stronger than the 4cyl.
please correct me if I am wrong