My guess is these were advertized figures and not the actual numbers. This was also published long before the cam industry started using a standard. I think Harvey Crane of Crane Cams(past employee of Iskenderian) introduced using .050 valve lift as a starting point for these measurements and the rest of the cam industry picked up on it. There some cam manufactures such as mellings and GM factory cams which still do not use these standards--.006 is used quite offen. With out some explanation as to the amount of valve lift and the location of the piston when these numbers where posted, who knows !! Ed Iskenderian was and still is quite an Inovater to say the least and he may have found some HP gains by letting the exhaust stay open longer. Just some thoughts--Paul
