With the key straight up and the top gear dot straight down, the cam is advanced 2 1/2 teeth. This almost always results in the intake valves running into the pistons...... Unless the valve pockets are really deep and/or the cam is really small.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads