about a week ago i hit a massive pot hole and my exhaust dropped off it would back fire sputter and try and die on me, i just had a shop put 2.5 inch duals on it with magnaflows no cats, my back pressure is back but i still havethe sputter plugs wires caps and rotors fuel and air filter all replaced within the last 5 months i have no idea what is causing this in nuetral it revs fine but as soon as you put a load on it, it sputters its a 1985 with holly 2bbl and new fuel pump