Narrowing my own 8.75. Questions.

Do not weld the spring spring perches until the housing can be mocked in the car. That’s what sets your pinion angle and is ride height dependent. A truck with 6” of lift and a valiant that’s 2” dropped will be entirely different. Don’t pick an arbitrary number and stick em there, it will be wrong. As for the housing ends, the only important factor with those is the orientation of the brake bleeders once everything is assembled. They need to be pointed up.