GM 8.5 10 bolt swap

Totally depends on the use of the 400 - 500 horse you speak of. To actually try to use it, and in what context. Or is it just to say you have it. There are researched and written documents that discuss the difference between your two choices. Some of the information deals with strength and some deals with power to the ground application. I do not remember every detail so I wont try to speak like I'm a keyboard expert here and misrepresent. I do remember that it boiled down to the pinion gear and ring gear relationship. They stated that the contact point of the pinion gear, either higher or lower in the base circle of the ring gear, created more energy loss. It also discussed axle wrap, strength and I believe heat build-up. The out come was that the ford axle was the overall better choice. The ford was supposed to have the overall end of the track advantage. I can tell you that I run a mid 10 sec nova at the track with maybe just a little bit more horses (he, he) than you speak of and there is no way (IMHO) the 10 bolt would survive as long as my 12 bolt has.