318 cylinder head upgrade

I used “O” heads on my 318. They came off a ‘73 340. I had 2.02 intakes installed, took .050” off the deck surface and .040” off the intake surface, and used an 1128G Mr Gasket head gasket. Chamber volume after milling was down to 58cc. Gained a full point of compression. Car has gone a best of 13.6 @99 with a very inexperienced driver (me) rowing the 4 speed.