Pinion angle posts are the most entertaining thing on Moparts.
That's why we do it so often.
What happens to the driveline angles in a leaf spring bracket or street car is totally different from what happens in a promod car. Your going to set it up differently regardless of what the popular standard theory says.
Never forget: "If it's wrong but it works then it's not wrong".
Does anybody stress this much over what happens to the pinion angle when your standing on the brakes?