if your dizzy was loose then you didn't have a proper timing. a back fire is unburnt fuel in the exhaust, so if your timing is off it may cause a cylinder to fire too late or early and not burn the fuel. You will have backfiring and loss of power very easily. Fix your timing and you should be golden.
it was definitely the distributor but the timing was good some how,but under the rotor button down in the bottom,i guess the pick up?or whatever its called was filthy so i cleaned it and now it run's great!thanks guy's for all of the help!!!