How can I tell what cam I have?

I bought my car from a guy who didnt know squat about it. The guy before him had to have known something because theres bolt ons done that I know the PO couldnt perform. The car has a pretty lopey idle sounds like its got a mild cam. Buttt the car has had a CEL since I got it. For all I know the car could be running like that for any number of reasons. Still I believe its got possibly a e or b 303 in it. Is there any way to tell what cam let alone if it has a cam in it at all?
 
Just a little side note: My B cam (all praise to B cam) didn't say it was a B cam. But then the B cam is so wonderfull that it makes all things around it just as straight and long as it is so it doesn't need identifying marks. You'll know when you have a B cam within 100 feet of you. It has even been known to make dead people stiff as a board if placed near their body within 12 hours of death.
 
My bcam also sounded amazingggggg, but mine was stamped b303 on the front.

I think your theory of an aftermarket cam is a little bit of wishful thinking, It's probably stock...