This is an original 1935 Chevy NOS Water Pump.  Good looking condition, not stuck, does not appear to have ever been installed-see photos.  Impeller diameter is approx 3" w/ 8 fins by approx 7/8" wide.  This has both '35 and '36 Chevy part numbers on it.  I believe this to be correct for 1935, but may also fit 1936-but not sure.  Please check my other auctions.