I have a 71 Challenger, auto trans, 440, Holley 600 cfm, electronic dist. Motor was completly overhauled and now produces around 375/400 hp ?? Installed the distributor with #1 cylinder on compression and rotor pointing to #1 cylinder. First attempt backfired through the carb, moved distributor ccw engine cranked normal, moved ccw little more and turned key to start position, nothing until the key went to the run position and the engine ran for about 3 sec. Engine tried to run after letting off the key. Any suggestions?