340 Cam

You guys think Cs method of calculating adv duration is confusing!

How about Pontiac. Post-1965 hyd cams were measured at 0.002" valve lift on the opening side & 0.008-9" on the closing side. Have no clue as to how that rationale was arrived at....Using this nonsense, Pontiac rated it's biggest factory cam the RA4 as 308/320* adv duration. The numbers at 050 were 231/240*. The Comp 280* magnum cam has 280* adv duration & 230 @ 050.
There were some ridiculous adv numbers advertised [ pardon the pun ] back in the day to see who had the biggest...
How about the Herbert #70: 400* adv, 279 @ 050.