Brumie, are you sure it's the stock cam from the F2? If it is, and you don't run it, I'd be interested in it. It's a good cam for a turbo motor because it has a little less overlap than an early cam and it's a little higher lift. From what I've been able to gather the F motors had larger valves and didn't need as much overlap to get a good airflow, so the overlap was tightened up for a slightly better idle. They also had a steeper 1st because the rest of the gears were closer, and needed a little more low-end to get going. No idea if it's worth swapping it into an early motor and what would happen. Probably not a noticable difference in a stock motor. If it is an F2 cam it'll have a broken ridge running around the end of it. Post up a couple pics if you're not sure. Cams get changed around a lot cause they're easy, and most people (like Sarge) just grab one.

Naguethey, you can get rings for the earlier 78F motors from honda still (can't remember the S/N range, like 231,000 and below) but not the later ones. No idea what changed, but no one's got 'em or makin 'em.