1971 C10 pinion angle

[silver7]

Looking for any advice on the correct pinion angle for 71 C10. I need to replace my current 12 bolt housing and the replacement doesn't have the leaf spring perches in the correct location I need. Before moving and welding I want to make sure they are moved to the correct location to ensure an OEM pinion angle. I can't say the original housing was stock so I want to make sure I set me current housing at the currect pinion angle since the superlift springs I bought came with a wedge set to keep the OEM pinion angle. Thanks in advance for any advice!