Whats a good replacement valve stem seal other than the rubber umbrella type? I am trying to find some for the heads i am putting together but all i can seem to find for the stock valve stem diameter is the umbrella type.. Surely someone makes a good Viton or Teflon Positive Stop type that you dont have to cut the guides.

 

If they are stock LT1 heads, you can get the positive viton seals straight from GM. Or go to a machine shop and tell them the size you need and they should be able to get them. I prefer viton over teflon on a street motor.

 

Gotta part number for the GM ones?