Back in the claimer days we had to do everything cheap as possible. There was a $325 claim on the whole engine and $25 went to the guy running the wrecker to pull it after the race. We were racing small block chevys. We would save the good gears and chains out of the motors we tore down. We would drill out the bolt holes and the locating pin hole by hand ( no drill press then) and use an offset bushing in the locating hole to get the cam where we thought it had to be. Seemed like they never moved the cam the amount the were supposed to. A lot of trial and error to get it right.