Ignition help

Heres my problem..its not camaro related but still chevy related...70C20 stock 350 4bbl...I seem to have a wierd miss at idle and then when I adjust the dwell the miss will shift to a diff rpm.. or it will back fire when I rev it up. Should I get new points? Keep adjusting the dwell( book says 31 degrees I think)..I put new plugs,wire,cap,rotor is working just seems to have a wierd miss at around 1800rpms right now. If I floor it its not noticable just at cruisng or gettin up to speed with light throttle...I get only 8mpg so I try to go light on the gas..any help appriciated