stupid valves seals

Yeah, we used to call them PC seals (Perfect Circle maybe? can't remember why) They fit tight on the guide and didn't ride the valve. You needed them for race engines and they were an nice upgrade for street engines too. Some applications you needed to machine the outer diameter of the guide but most of the time we could find one that fit without doing that. The regular umbrella seals should work fine in most apps but if you have worn guides, you'll need the PC seals to even have a chance of cutting down the oil burning.