I just looked at Rock Auto's website and it looks like all small block chevrolet engines use the same oil pump drive, Sealed Power #2246146. The Big Block engines use a different shaft and if its a big truck Big Block (Tall Deck) They use a different shaft also. What part number did you get from the parts store? Maybe they gave you a drive for a big block?
I can check the part number on the shaft they gave me to match up with my HEI distributor.
But that is not the issue at present because currently the oil pump and drive shaft is removed.
Wish I could figure out how to post a pic?
