I was going thru some cams I have, and I acquired at some time a "509" BB cam. It has no stamped numbers on it. I calipered the lobes and base circle to determine that it was a 509 lift cam, but when I looked up the rest of the specs, it turns out there are two 509 designs. (The earlier) one has 76 degrees of overlap, and the later one has 64 degrees of overlap. The later one was changed to make it more streetable. Anybody have some trick idea on how to determine which one I have, without installing it and degreeing it in the engine?
