Finally get to pretend I am one of the cool kids - Holley kit swap
Never cared what the actual angle was because I was just trying to get it tight to the floor to give me good clearance.
One of my slow downs has been that I fixated on the motor angle way too much. Since I am cutting the floor and crossmember out and building my own, I am pretty free and don't have to worry about getting it tight to the floor. So I felt like I could shoot for the "optimal" angle, whatever that is. The instructions for the Mopar crate motor kits says the motor sits at 2 degree in a Challenger, so that's where I started. But 2 degrees relative to what? If it was to the ground, my chassis probably isn't at the same rake. If it is to something on the chassis, then what do I reference it to on my chassis? And thus the swirling water in the drain swept over my head and I wasted way too much time trying to just get a breath.
In the end, it finally dawned on me that the optimal angle is the one that fits the u-joints.
I would like to put this together with the rear axle that is in the car and not have to build a new one or fix the pinion angle on the one I have as part of the swap. There are plans for a trick 8.8 later on, but that's for when I start looking at ABS and 18" wheels. The first drive will be on a more stock chassis and I don't want to have to mess with the rear axle to do that. In the end, my 3 degree setup should (in theory) mean the u-joints are happy even if the pinion angle is lower than I read it should be.
I still don't understand why my pinion is low either. seems like it is way off what it should be and the axle is factory stock, just an A-Body 8.25 on stock (but good) 6 leaf spring pack. The car really isn't even lowered in the rear from stock. But the front is lowered a fair amount, maybe that's the difference?