I like the Pinion Angle to be set the same, 1-piece or 2-piece.
No math. That is why people suck at setting pinion angle.
I measure the pinion flange against the crank damper.


As was just posted, and says in that drawing, you can use the crank damper.
On the rear end side, there is a flat machined spot you can use on the flange.
+1. I think a pic would go a long way to show where to place the angle finder on the pinion flange. I would post a pic but the car is at my shop.....
When I have the car back up in the air, I will snap a pic. You have to hold the angle reading device somewhat firm against it, it is a small spot.

It has a taper on the outer edge. There is about 3/4" of perfect flat to use.