I found 2 different oil pumps. One is much heavier than the other. Can anyone give me an answer as to what the difference is,& what they were used on?.

My records show the Big oil pump was used from 5/2/52. So all late production and later military engines used it.

Is the BIG pump better than the regular?? More capacity?

The larger pumps that I have are from military units.

I found the heavy pump has 9 teeth--very close. The smaller pump has 10 teeth-not close--the tighter the teeth the better the pressure.