[GOSFAST]

Most standard bore gaskets are 3.270", on a .060" over (3.250") the risk of having the "fire-ring" too close to edges of the bores is much too high. There's a real possibilty a portion of the ring will hang over the edge at 3.270". You may be "splitting-hairs" so to speak.

I would go for the 3.420" and have a decent safety-margin!

Thanks, Gary in N.Y.

P.S. We try to stay with the Fel-Pro line, never had a single issue so far. We do use the 1-pc front seal on all builds with the respective sleeve!