Tom is correct in that high volume pumps are not needed but I always used them in Clevelands for a little added insurance. It seems like I always end up with bearing clearances on the loose end anyway. I have no experience with Precision, but a while back, on another forum, several were speaking highly of their work. I think they grind the ends of the gears and the pump cover for proper clearance then lap the gears for smoothness? (Years ago, we used to primitively sand the ends of the gears and cover face on a piece of glass covered with emery cloth.
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