There is a gotcha for timing for small block Chevys that can cause problems if overlooked . User "oldboogie" at the forum at Hotrodders.com said, Unless you appreciate that the crankshaft and damper pass the timing tab twice in a revolution which puts different events happening at each place because the cycles (of the cam) are happening at half the rate of the crank. So for argument starting at a point where both the number 1 and number 6 pistons are at TDC lets say this in cam (thus distributor position) is ready to fire number 1. At this same time the cam has number 6 also at TDC of crankshaft but it is finishing the exhaust stroke and will commence the intake at the same time number 1 is on a power stroke. At this point if the timing cover was to be removed the timing mark of the crank gear and the mark of the cam gear would both be in the 12 o'clock position. Now rotate the crank one full turn, both number 1 and 6 are back at TDC but number 1 is fi...