Pinion angle question

No, because the springs need to be at ride height and the frame level before any measurements are taken.
I still don't understand why it would matter if you weld the perches on the axle while its setting on blocks the ride height isn't coming into play either if its suspended on the leaf springs or suspended on blocks level is level I dont understand the difference. But I trust you and trust your opinion so I will pull it back out and do it on blocks