Is my rear end strong enough

BS on upgrading. I have a friend who has a Demon that had an 8 1/4 in it. Car ran 11s yankin the wheels leavin. He upgraded to an 8 3/4 but not because he broke anything. He was upgrading the whole car. He still has the 8 1/4. They are plenty strong.

I agree. I put well over 450hp through an 8-1/4 in a 4800lb truck and ran 12's all day long for years in it. The trans lost 2nd gear before the rear end even blinked at the power.