In the lates 60's ... whenever the Horsepower was rated over 300 or so ... Chevrolet installed a 12 bolt. All the factory big block Camaros, Chevelles and Novas came with the 12 bolt.
Your 454 has more torque than the 396 engines that Chevrolet had in front of the 12 bolts.
If you drive conservatively ... the 10 bolt can last.
I bought a new 69 Nova SS ( 396/375 HP - 4speed ) with the factory 12 bolt POSI. I killed a couple of the 12 bolts before I upgraded to a 31 spline 9 inch Ford. This was a street car with almost no drag strip use. I did street race ...
S T U PI D
and against the law ... but I was young ( 21 ) and fearless .