Good morning all,
I just came back from a shakedown run, and when I run the car hard and shift manually, it throws the alternator belt. If I leave it in drive and nail it all seems ok. I just put a new March alternator bracket on last week, and the alternator seems to be held rather well. It only is doing this if I shift manually, over 5500 RPM. The engine is a 355 in a 71 Nova. Any help is greatly appreciated.

Tiny