Had a buddy years ago with a set of these (no work, straight out of the box as I remember) on his 467 BBC in his '68 Camaro. 12.5:1 TRW's, .714 lift solid roller, 1050 Dom. carb.
Ran 10.50's in the quarter on the biggest, fattest M/T street tires they had at the time. Although they are a bit heavy, they are great heads!