Put on my new SS 19P on my PT175 w/75 Merc. WOW what a difference in performance.I had a stock aluminum 21P before.The SS is about the same RPM a little more speed & the handling is WAY better did'nt exspect that,It now wants to turn when I want it to!It does have more gear whine from the SS prop,but I don't mind.Oh yeah the hole shot is way better too.