I've always preferred the 068 factory grind for a 400. You could have the heads clearanced for 1.65 rockers for more lift.
1968 400 Coupe, verdoro green, black vinyl top 1968 400 Convertible, verdoro green, black top 1971 Trans Am, cameo white, auto 1970 Buick Skylark Custom Convertible 350-4(driver)