Yeah, I remember when talking to other car guys in the 80's when I was really into that stuff, that there would always be some yahoo who would hear us mention something about fast cars who would butt in and talk about their buddy/relative/ friend of a friend, who had a "3/4 race cam" and his car was the fastest, baddest, etc. It was always obvious that the person butting in had no idea what he was talking about and that it was a real whopper he was telling us. Now, there may have been an actual thing that existed somewhere, but when I would scour all the sources I knew, no one could tell me what one was.
It was pretty much a term guy's who were not gearheads used to describe a cam a little hotter than stock, Didn't know the specs on the cam.
