There for my 11/32'' valve (Staineless steel) and .530'' valve guide cast iron heads.
It will have a no hotter than a 180 thermo, Mobil 1 oil, wet sump oiling, no valve stem cups, single spring with a spirl damper, .511'' lift, top engine speed of 6500 rpms, forced induction (TT's), direct port fuel injection (some fuel contact with intake valve stem), most likely be run a little rich, it should only pull about 20'' of vaccume and have a low $ engine crank case evacuation pump.
Teflon is said to be for race engines and viton is the better stock replacement.
What do you think I should run???
Viton or Teflon?
I have been to the Viton web site and seen all its specs when used as O rings and pump seals.
Teflon is teflon I use those seals all the time on hyd system seals to gas turbine compressor stage seals, many uses.

 

Go w/the Viton. Even if it turns out to be overkill, you have that extra insurance & a good feeling in the back of your head.