How much horsepower is too much for small bolt pattern stuff?

I have a buddy who had a street/strip 73 duster with a eddyhead 340, 150 shot of NOS, 3:91 gears and adapters to go SBP to BBP, and I cringed everytime he made a pass, it would run 6:80 1/8th mile which is probally 10:90 in the 1/4, never had a problem.......