I have 1994 Mustang GT with about 2k miles on it. H/C/I (TFS stage 1) I had originally bought an Oriellys replacement distributor. After 3 months the pin sheared off the distributor. Returned it for a full refund and bought an Summit Racing billet aluminum distributor. It also lasted about 3 months and it sheared the pin again? Any guesses on why? Both times it was shortly after start up, revving less than 3K rpm. So far after much research i'm hoping its not the oil pump that is seizing, I don't want to go thru the expense of taking the engine out again. Any suggestions would be greatly appreciated! The distributor has lint not metal shavings.
I have an msd dizzy for sale if you want to try that! Anyway, is it a stock oil pump or high volume? Did you drain the oil? - check for particles and/or coolant You can try to spin the oil pump to see if it has any hard spots in it. Find the right size deep socket to fit on the pump shaft (1/4 or 5/16 maybe?) and spin it with a ratchet. McMaster Carr has coiled roll pins which would be much stronger than a conventional roll pin, but sounds like you have more of an issue than just a weak roll pin.
That's a weird issue, what is your oil pressure? What pump do you run? Not sure what would add stress to break a pin. I've locked up 2 oil pumps due to debris and each one snapped the oil pump driveshaft. Never have I seen a pin shear like that. The gear should be pressed on and not move whatsoever. How is your cam? Any signs of wear on the cam's distributor drive gear? Could this be due to bad oiling in that spot?
I would be curious to see what the issue is too, certainly not a common problem. I'd look closely at the gear on the cam, wonder if it has a rough spot or is out of round and pushing on the dist gear.