Joseph Donnelly
TDR MEMBER
I used one shim about .075" thick iirc for the 215 hp pump, ID about .5" so it was a snug fit on the stem of the retainer, and OD matched the spring under it. So long as the spring under there (#3 going inside with 1 being the idle spring) is fairly stiff, the technique works. Max rpm went up from 2750 to about 3500.