wrench87 So far my poly gear is working fine. I see no wear marks on it. If you call Crane, Comp, and Isky you will get a different answer from each tech you talk too. If it's a KCR custom cam shaft, Call Kieth and get the gear he runs. You can break the motor in with any gear but have to watch and see if a wear pattern starts. Biggest problem I have seen is the intake manifold is not located in the correct position on the block and the distributor is off center. This causes extra wear on both gears. Having an
oil supply to this spot also helps stop any kind of wearing. Run the motor 100 miles and pull the distributor and check. Do this a couple of times and look at the teeth edges. 1 other note, was the camshaft end play checked? This will also per wear parts. Rick L.