I picked up a Holley 6299-1 (390 CFM 4-barrel) at a flea market for really cheap so I couldn't pass it up. Definitely in need of a clean and rebuild when I get a chance to tinker with it. No, I'm not going to put it on my big-cammed 451 whistling

Can I glass-bead everything I want to clean, or only the outside of the body, or not even that? work

I am concerned that it would have the same effect as glass-beading pistons (i.e. abrasive gets stuck in the surface of the metal and wears the crap out of the bore as well as ending up in the oil)... pot-metal isn't very hard either.