for somebody that's been around, or says that they've been around cars for as long as you say, i can't think to be shocked about this. but, here we are. basically it's a toned down full race cam. here's the straight dope:
also here's an article:
[URL]https://www.enginelabs.com/engine-tech/engine/tech-quickie-what-is-a-34-race-camshaft/[/URL]
3/4 race cam is kind of an all encompassing term these days.
