12 bolt

[JW76]

I have a 12 bolt out of a 1969 truck with 3.73 gears. I am putting it in my truck with a TH400 with a manual valve body. I will eventually build a 6.0 that makes 500 - 550 torque for the truck. Will the 12 bolt be able to take the abuse? The truck will mostly see street use with occasional runs at the track. I've heard that the pinion shafts are smaller than the cars and break quite easily. I intend to use good Moser axles and a C clip eliminator kit if I use the 12 bolt. Thanks for any input.