As far as I know all FH valves were peened at the factory. I've had several made with keepers (too lazy to peen them!). If your engine has keepers chances are someone lazy like me has replaced the valve in the past.
Putt'n a pin in the intake stem may be the lazy way but personally i think it's a home made improvment. You ever have to lap the valves, pull the pin, have the valve out, lapped, put back in, in less then 30 Min.