For aftermarket to work, all that is actually necessary is to drop the distributor in on the #1 cylinder compression stroke at TDC. Your rotor will point to the "new" #1 on the distributor cap. Start there with #1 plug wire and follow the firing order around the cap one wire at a time tracing to the cylinder as you go to be sure.
If you really want get #1 back to the same as stock orientation on the cap (as I see in your last post), it would be necessary to index the distributor drive (I believe your terminology is "cam gear"), the required amount.
Then too, if you are going to machine a drive flat on a shaft you can locate it where ever you want. You could make it the same as the stocker.