A lot of old mechanical cam grinds have significant valve train noise. The Oregon 346 has a pretty tight lash setting so I would expect it to run a bit quieter than most cams with similar lift and duration numbers. If your compression ratio really is 10:1 it should idle reasonably well, but have a serious exhaust note with a performance muffler. Degree the cam with a 100-102° intake centerline. What makes exhaust noise is residual cylinder pressure when the exhaust valve opens and the exhaust system itself. I haven't run this particular grind myself. I bought a #791 as I wanted more exhaust duration to compliment a nitrous system. I still don't have that engine in the car though.
