Bad lifter? or loose rocker?

[Rev]

I have to replace header gaskets every 6-12 months on my car. Usually after a few WOT runs at the track. For me, it's only a 1 hour or so job and about $15 for new gaskets. That's with Tri-Y headers. Ive done this 4-5 times now, so I'm just resigned to it I guess.

Rev

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'66 Coupe, 306, 300 HP, C-4, 13.97 e.t., 100.3 mph
1/4 mi.