I just bought a 1968 Mustang for my son. It didnt have an engine, so i put a 302 in it. The first time i tried to start it, the thing rurned over when the key was turned to the on position and also the accesory position. When the switch is turned to the start position , nothing happens. I have replaced the ignition switch, the starter relay, and even the starter. To my amazment the thing still doese this. Does anyone know what I am doing wrong to fix this?