It sounds like the end of the distributor is not seated properly inside the slot on the oil pump. Sometimes when I install a distributor, I have to raise and lower it several times until it slips in. If that doesn't work, inspect the end of the distributor shaft for burrs and use a flashlight to see if there is anything restricting the slot on the oil pump.

Last edited by buoymaker; 05/30/2021 5:47 PM.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."