Which headgaskets should I use?

putting in performer RPM heads on my 340. Which head gaskets should I use? any that I shouldn't?

Since I take it your just doing a head swap on a running motor then I'd use the .039 thick FelPro's permatorque's.

If you are at zero deck & those heads are closed chambers the .039 ones mentioned would be just perfect. be sure & check the part #'s & thicknesses as the ones I have(felpro blue) are alot thicker than .039", there may be 2 different ones(.054)??,I'd have to go measure the ones I have.

FelPro composite gaskets, # is either 1008 or 1009. Never a problem, even at 13.0:1.