The trick I show you in here on how to EASILY get the oil pump drive shaft to line up with the distributor is credited to ‪@Myvintageiron7512‬ one of my all-time favorite channels that I've been watching for years. Check him out and see for yourself what a great guy and great channel he has going on.
Ok, so there is nothing more frustrating than trying to set a distributor down in the hole, only to find out that you are 180 degrees out, so in this video I do my best to show you the A Number One way I've always done it to not only avoid that, but how I correct it if I come across it. You can't go off of general information on this, because contrary to popular belief, Chevrolet pointed that rotor on that distributor in many different places depending on year, make, options and model in order to make enough room for you to "fine tune" it with the vacuum advance hanging off the side of it.
I'm showing you this on a Small Block Chevy (sbc) but you can use this on any make and model engine that uses the camshaft to drive the distributor.
Hope this helps you as much as it's helped me through the years and as always...... get out there and "Keep that Metal Hot".