Pinion angle question

Yea the leafs are at full droop the car is all the way up on blocks and the rear end is setting suspended on the leafs.
I'm just thinking outloud so feel free to correct me if I'm wrong but if I do it the way you said and put the perches level and the pinion 5 degrees up wouldn't that be the same thing I'm just using the leafs to suspend it instead of blocks ? Please dont take this as arguing or disagreeing I'm just trying to learn lol my brain is melting trying to figure out these damn angles

No, because the springs need to be at ride height and the frame level before any measurements are taken.