We use the Comp 10 degree on most of our engines thst use a shelf stock valve with square grooves,no failures with thousands of runs logged.We use Bead Loc@ radius grooves 10 degree when we order custom valves,and again no failures.Bill C.

Ceralli Racing Engines & Checkered Flag Machine Racing engines , CNC porting & induction development http://www.checkeredflagmachine.net/