I am very new to this so I will lay it all out here. I have a 1971 Plymouth Duster. It has been sitting in my grandfathers garage since 1991 and I just got it earlier last summer. I have redone the brake lines and was starting to work all the bad gas out by changing furl filters over and over. I had it running two weeks ago and changed the radiator hoses, fan belt, and antifreeze twice by accident. I then drove it back into the garage and now it won't start. It cranks and tries to fire if I hold the gas pedal, but never takes off. I replaced the carb, plugs, wires, starter, and now am out of ideas. I checked the spark at the plugs and it is sparking. Please if anyone has some help.