Speedmaster Small block porting tips and results Part 1

Well if you would look at my pinch measurements on around page 15 you will see Stock was .930, cnc’d was 1.015, and tubed was 1.040 kissing the tube. There really isn’t much safety room on the cnc’ heads (.025) which isn’t much when you consider core shift pouring heads and machining them. Personally I think I would tube the cnc’d heads if it was me. One 10 inch stick of 17/32 K&S tubing, a tubing cutter, and some JBWeld and you’re good to go.