The Zeus heads have the word "Zeus" cast right into the head and had the least issues.
Someone will have chime in on this...... But as I remember it, the Chapman stage vi's were cast by the Zeus foundry as well, although those were their own casting.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads