Ok, here is a strange problem. On my buddies 66 chevelle the power steering belt gets thrown off about every three weeks. This never happens under load, only thru slow corners when steering makes it back to center (i.e from stop sign taking a corner) Now we went to a deep grove pully on the crank because that was where it was coming off.(belt was hanging on pump) Now it has thrown it again. Does anybody have any suggestions? We have gotten into the throttle hard and never tossed the belt. Could the pump have a bad spot?

Any help would be great,

Thanks

How's the pulley alignment? Is everything straight from the side(the belts)?

It seems to be just a touch off, tried shimming it, seemed straight but still thru the belt

I think even if it's a little off then it shouldn't let it fly off anyway. Sounds like you have some power, you should get all deep groove pulleys. My brother's camaro had the same problem when he went to the track. He has all deep groove pulleys except for the power steering.