I have an 72 dodge challenger that im having isues with. At random times the car will stumble and at times the motor will quit. This can happen most frequntly from a start. I now the fuels system is all good caused i have replaced it all. I know the timing to be correct. Like i said it is random this am the car worked great no problems on the way to work. This afternoon i didnt know if it would make it home. Any suggestions?