508 or 509 Purple Shaft cam

I see a 508 there but not a 509. My 360 has what I believe to be a 509 cam in it. My mechanic did some measurements and that's what he came up with. Don't know anyone with a cam doctor around here to find out for sure though. I want to degree the cam properly when the engine goes back together. I thought about just getting a new cam and bearings but money is just too tight now so I'm just regasketing the engine to get rid of the annoying oil seepage. It ran like a bear but since it's apart, why not make sure it's correct?