Is a 7.25 rear strong enough?

No mention of the '66 B body rears? I have a housing with everything except the punkin. I Have a 3:91 peg leg in the shop.

My present 7 1/4 is a peg leg 3:23 with 67K on it. It hasn't moved since 2009.

Neighbor has a 8 1/4 in a van with 3:55's and a sure grip. He wants too much for the van. I guess I can gut the gears and put them in a A body 8 1/4.