driveshaft angles

I dunno, A body has the perches level and the pinion pointing up 5*.

If the trans output is at 0*, regardless of position with the ground, the pinion should be in the 2-4* down position to account for roll up under cruise.

Anymore than 4* usually starts to strain the U-joints

JMO and this

View attachment 1716047232
That's how I've always done it. Make the pinon parallel with the trans/engine centerline and rotated it down 2-4*. Easy peezy.

Why even include the driveshaft in the equation?