Lapping your own valves in your cylinder head may seem intimidating at first but actually its a very easy process that you can accomplish in your own workshop.
This easy process will allow you to reuse your old valve stems and help prevent loss in power and solve and compression issues.
These Heads are off a 1972 Harley Davidson Iron Head Sportster where the engine literally lit on fire and the pistons melted.

Check out the Tear down of this Iron Head on Episode 3:
   • Crude Moto Ep 3: 72' Iron Head Choppe...