I'm overhauling a 1970 PL521 truck engine. Reference Haynes mannual
Installing the oil pump, gear and shaft
1. TDC #1 piston
2. the offset dog must face the front of the engine
3. the dog must be set athe4 11.25 o'clock so that the smaller bow shape is towards the front of the engine.
After installling the distributor, the vacum advance assy. is 90-180 degrees out. It in the way of the exhaust manfold.
suggestions please
Billy Lee