my problem is now my 78'chevy truck with a 350 is running badly. it all started when i removed my HEI distributor to see if it would make my camaros engine because it was missing at idle, so anyways i put my trucks distributor back in and i fired it up and and try to set it at 8 degrees. but the engine ran rough and some time would die,so i thought i had a vacuum leak i thought it was the intake manifold gasket, so i replaced it. also when i had the carb off i cleaned it up since i had it off. i put every thing back in place and tryed to fire the engine up and i set the timing once again at 8 degrees still it wanted to run really rough,so i thought it was maybe the spark plugs sinc i have not changed them since almost 2 years ago so i put some new plugs and a new ditributor cap and rotor since it looked worned out, and also i put some WD40 one the advance weights ,becaus they look a little rusty i moved them around to see if they where stuck and worked some more WD40 in so free the advance weight up. i put all the parts togeter and still the engine runs rough, it sound like a tractor or a diesel. when i advance it by alot , it will sound like it should and runs smoother, but i know it should not be that advance at idle.
now I'm out of ideas any suggestions would be greatly appreciated