Will a stock 8 1/4" SG with 3:55's hold up??

Yes, I was thinking of Dr Diff 30 splines with green bearings?
I am installing their rear disc kit and going from SBP to LBP.
Any comments or suggestions?
I also haven't picked a final gear yet. I have 3:23 pumpkins but a lot of A bodies run 3:91's?
I'm thinking 3:55's? I guess I will see how I like them with the 8 1/4" first??
I am going with the widest 15" tire without mini tubbing yet??
Probably a 255/70/15 or 255/60/15