Tech, thanks. I was of the impression you needed pressure induction (turbo, blower) to get past 100%, but headers and enough overlap will help with the charge velocity, and the good heads no doubt help. He's got the angle-plug bow-tie heads that were the hot ticket in 1977, and did a lot of port work on them.

The 428 seems to work out about as it should. It sort of runs out at 5800 with the 735 Holley, and that worked out to about what it needed. Sounds like I need to go bigger on the cammed up 410 (+.060). I keep saying there's as much art as science to this.