Just wanted to let you know the 400 runs great & sounds great.
Thanks to Latech, Cobalt, Thumpin455 and all who helped with this project. It's a mild build with 6x-4 heads milled, ARP 7/16" studs, poly locs, Sum2802 cam & lifters, shorter Crower p-rods, new timing set, new oil pump, and headers.
Now the tuning begins. Later work includes a ignition advance kit and a numerically higher axle ratio.
Thanks again for your help.