What we don't know from the catalogue sheet is whether those duration figures include clearance ramps. That's why the 0.050 lift figures are helpful, because that eliminates the clearance ramps. I bought a Howard's cam of that era and the data sheet did give the 0.050 figures along with the advertised figures and lobe centers.
FWIW the Howard's grind was indistinguishable from stock on the road but was advertised as a 3/4 cam. When I mic ed the lobes it was so close to stock I couldn't tell. It might have been one of the "stock-class" cams that had the same lift and duration but a higher lift rate so you could cheat and not get caught at the drag strip. But then who wants to go to all that trouble to "claim" a stock Chevy 6? I could smoke most of a cigarette waiting for one of those to clear the traps at the end of the 1/4 mile. (cheap tobacco).
