I’ve got a 340 project I’m building for the street. It’s a 4.00”stroke with 4.080 bore and aluminum Edelbrock heads. I can go with the felpro .050 gasket and get 10.27 or the thinner .030 Cometic and get 10.45. The cam is a custom ground Bullet cam that will have about 14” of vacuum for power brakes. The pistons are race techs with a reverse dome and -.004 deck height.