I have a '77 Pontiac Trans Am with the original 400 Pontiac engine, but it has several modifications. It has been switched from hydraulic lifters to solid lifters. I believe it has a different cam, and it has an aftermarket Turbo installed. The mechanical fuel pump just went out, and my mechanic is noticing some loose lifters on one side of the engine. He can't remember what the clearance ought to be, though. Anyone know?