Head gaskets...... Not really a good place to scrimp IMO. I'd stick with the 4.410 Cometics.
What you're experiencing is why I prefer not to try and make a head into something it's not by excessively porting it. If you need a bigger head....... And something is available.......its often less expensive in the long run to just get them at the start.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
