The Summit 2801 cam works great in a 400, 8:1 up to 9.5:1 runs great! I have ran as well as 13.3'
[email protected] mph in mild/stock-ish 400 ci 400 2nd gen's birds with that cam. Definitely use the Qjet intake with heat riser/egr blocked off and find a 800 Qjet from a 76-78 Pont 350 or 400 use a 72/44 or a 73/45 jet/rod primary combo, Trans Am or Bonneville ,etc..
Use a recurve kit in the HEI with the lightest springs and set total timing at 34-38@1600-2000 rpm and don't use the vacuum advance and 160 degree thermostat. You should be well pleased with the performance!!