I HAVE A 84 CAMARO W/600CFM EDELBROCK CARB, MY CAR HAS A VERY HARD MISS IN CAR. IT IS ONLY NOTICELBE WHEN THE CAR IS AT LOW RPM. AT HIGHER RPM YOU CAN'T NOTICE IT. I DON'T KNOW IF IT'S SOMETHING WITH THE CARB. OR DISTR. BECAUSE I CHANGED THE IGNITION MODULE, AND THE COIL, I DON'T KNOW IF IT IS THE CAP AND ROTOR, ANY INFORMATION WILL BE NICE.

 

Vacuum leaks affect low RPM/light throttle much more so than they do at heavier throttle/higher RPM. The amount of air sucked in through a vacuum leak at idle is huge compared with how much air is flowing through the carb. At higher throttle openings the amount of air flowing through the vacuum leak is relatively inconsequential compared to the large amount flowing through the carb.

Also, if valves are tightened down a little too far you can hang a valve off it's seat slightly and it'll idle like a top fuel car, but run good at higher RPMs/heavier throttle. If this problem popped up all of a sudden and you haven't messed with the valve adjustment then you can rule this out- this won't just all of a sudden happen one day. Vacuum leaks CAN pop up anytime- vacuum line falling off or being bumped off accidentally, degrading of the vacuum hose or some component that's attached to the vacuum hose, etc.

This is not ALL the reasons you could be having this problem, but it's the usual ones, given your symptoms.

 

a miss can be caused by a lean condition, or an ignition issue.....most likely a plug wire or arc over at the coil or the cap.

i had a bad miss, and i switched to a procap from MSD for my pro billet dist. and it solved the problem