It's not as bad as the 360 but the 350s have an issue with the oil ports being smaller than they should be. So... At high RPMs the oil gets "foamy" and doesn't do its job properly. There are a million how to's online showing the ways to fix it.
As far as cams...
Any cam from 68-73 will work. In fact, if you can find a Type 1 cam from 68 it's actually a slight upgrade from the later models which were slightly detuned.
In the end, they made more CB/CL350s than any other bike in the 60s-70s so parts and info are beyond easy to find. Good luck with your project and keep us posted.