Gears & Axles - Big 10...

I seen a GN that runs 5.05 in the 1/8 the other night and the rear end cover said Big 10 on it. The guy said it was a 10 bolt GM rearend. I've also been told about this "big 10," but am not clear on it. Anyone have any idea wtf I'm talking about?

Thanks.

It's a 8.5 ring gear not a 10 bolt 7.5 thats in a f-car.

Thanks....looks like that option is out the window.