Patrick had a bit of P.T. Barnum in him, I believe. The only way to be sure what you have, camshaft-wise, is to do a degree check, which isn't really all that difficult. All you need is a magnetic base dial indicator or two, a degree wheel, and enough common sense to follow the instructions published by the people who make racing camshafts. In very general terms, any cam with an "advertised duration" of over 280 degrees or so belongs on a race track, not the street. That's about where other engine mods like increased compression and improved cylinder head breathing, plus modified carburetion and exhaust becomes necessary to take advantage of the cam's "improvement". That's also where low end torque starts heading for Never-Never Land- - - -never to be seen again.
Ignore the "duration at .050" lobe lift" specification- - - - -it's a fantasy dreamed up by cam grinders to hide sloppy quality control concerning uniformity between cam lobes for a bunch of cylinders that are supposed to be the same near the base circle. A properly ground cam will begin and end the lift off the base at exactly the same point, no matter which cylinder you choose to measure. The first few thousandths of lift are where the "clearance ramp" is- - - -which also just happens to be the valve lash setting. For instance, if the first 16 thousandths of lift happens very gradually, then the lift rate increases dramatically, that's where that lobe needs to have its clearance set with the engine fully warmed up, to account for pushrod and valve stem stretch due to heat. My general rule of thumb is to set the "cold" clearance .002" wider than the published setting on a cam card. It's remarkably accurate, regardless of who has ground a specific cam. Have fun- - - -that's what hotrodding is all about!
Jerry
