I wanted to upgrade my modified stock dizzy with a MP unit so I could start playing with the total advance. I noted which way the rotor was pointed so I wouldn't drop the new one in 180 degrees out (this is a 400 BB). But the engine wouldn't start, just backfired thru the carb. Obviously the initial timing was wrong. I went back to the old one (which I have a little notch in at the base so I can put it exactly back where it should be) and everything was OK again.

If I put the new dizzy in again, this time ensuring the rotor points to the same wire on the distributor cap as the old setup, will that be close enough to get it started?