Valve stem seal preferences?

[Jack21]

Heads on motor are TFS Twisted Wedge aluminum.

When assembling the heads, TFS specified using viton rubber seals. Their rationale was that the valve guides needed the extra oil to properly lube the valves and guides. If this were true, then any canted valve engine would have the same issue.

Even my grocery getter rebuilds get teflon insert seals (Perfect Circle), if not all teflon (Crane).

The machinist thought I was crazy for not using teflon, but installed the viton seals. Should I have listened to my own (and my machinists) instincts? Use teflon, not rubber?

Since new, motor has used about a quart of oil per 1,000 miles, and it shouldn't be using any.

What valve guide seals are you using on TFS heads, viton, or teflon? Anybody using teflon having any valve guide wear problems? Anybody using viton having any oil consumption problems?

Engine has a little over 14,000 miles on it so it should be broken in. Used 10W30 to break it in for 3,000, miles, then Castrol synthetic.