The commonly published duraation numbers ( @.050) for the SK882 and C7FE LeMand cam are 252* with a .330 lobe lift which gave a gross lift of .528". TRW later sold the same cam (TP109) but advertised the lift at .508" or the net lift with .020 lash.
The C6FE-B cam was a "slight " bit different duration on the exhaust @ 254 and a tiny bit more lift at .536 gross. This "exhaust profile" later became the Shelby "SuperSnake 291" as a single profile ( intake and exhaust). I would have to check the #56 Engle I still have but IIRC it was 258@ .050 and had a .350 lobe for .540 net lift. It was a single pattern ground on 108" lobe separation.
Ford was VERY limited on cam profiles . ''Sully" ( Don Sullivan) spent allot of time on "cam phasing" which is comprised of lobe separation and advance and retard of the camshaft in the engine while using the profiles Ford had. A bright young engineer named Don Tewles (later General Kinetics Cams) used the Ford computer to design cam lobes and go against the grain of hand drawing and calculating cam lobes. This didn't set well with Sully but he relented that it was the future of cam designing. The new computer profiles carried new names like E1, E2, E3,E4 etc. These became the Trans Am , Nascar 366" and drag race 427 profiles or DOZX -A , D1ZX - AA , C8AX-D. Obviously first released for the 427 ( in tunnel port configuration). When first released as the 427 cam , it did not require the special radius tappets that the 302 and 351 needed. This was a direct result of the higher rpm operation of the small block engines and higher load springs needed to control valve float.
Randy