Look about half way down the page at "68 Rearend Swap"
I have not tried this - I'm after something a little more difficult - but it's not an uncommon thing to try.
... and, yes, the 10 bolt stock rear end will take horsepower, but the 12-bolt and the 8.5 were both designed to handle the higher torque of the 455 HO. (The 12-Bolt was put into the 1970 GTO behind the 500 Ft-Lb. 455, and in the 1971/72 TA behind the 455 HO.)
