[96capricemgr]

I will not argue the possibility of the canister control valve.

I will however ask on what planet you come from does a 305 not have adjustable valvetrain???

I based my guess at misadjusted valvetrain on my direct experience with my old 1984 305 Caprice. Back when I was new at mechanicals I made the mistake of thinking an exhaust leak was a loud lifter and adjusted them using the "spin the pushrod" method and had the bad idle, no vacuum symptoms he described because on my first attempt I set the preload much too tight.

The blacks smoke and smell of gas comments he added afterwards do not fit what I saw with misadjusted valves though.