Special Driver machined to contact THREE surfaces at same time to provide uniform drive.
The a) stationary flange b) Spring loaded seal c) The nose of the dynamic portion of the seal.
Samples, I like the Long pumps as the bodies are beefed up, I think in 1972 GM revised the waterpump bodies which use a larger shaft and bearing combination, so you have to be careful which kit you order. The squatty short pumps MUST be supported by the body not the legs, Don't ask,,See my numbers matching Z28 pump I shattered!
I saw a fellow in or at the Prtland Ore Swap meet in April and he sells the seals in addition to the Kits
Arg!!! I lost the business Card, CRUD!
JIM