MP distibutor

if you do the later choice it will work fine. I would have marked where the old rotor was pointing and install the new to match. I am guessing what motor you have but if small block it can only be on or 180 out, if it spits n farts out the carb flip it 180 and it should run. I am in long beach, if you get stuck later i can come out and give a hand later today or tomorow.