Cam identification how-to??

Finally got around to ID'ing the cam (I think).



I put a dial indicator on the cam lobe and measured .3155" on lobe lift. The shaft was purple as well. Am I correct in assuming I've got a 280/474 MP cam???

Are these decent cams? I like the way it sounds, but I can't get it to produce any more than about 10.5" of vacuum at idle. I'm hoping it'll run better after swapping the old Torker 340 for an Air-gap.