As you insert the pump the shaft is going to turn about 30 deg or so due to the angle of the gear teeth so it's a matter of trial and error. Just set the shaft 30 deg off of what you want and it should line up. If not then move it a tooth one way or the other until it does. One caution is that the distributor cog is just barely off center so it's possible for you to mistakenly get it lined up 180 deg out - ask me how I know
If you discover this after the engine is all back together the solution is to re-time the cams 180 out and you'll be good to go. But you're not gonna let that happen 'cause I just warned you...
