Yes you make good points with the driveshaft angles Brew. I've been reading into this today and seems like many GM passenger cars from this era had a small offset to the passenger side too. Now I'm assuming this offset is built into the motor mount locations as well. So essentially, if this is true, if one centered the transmission output between the frame rails with the front motor mounts having a small offset to the right, the engine would be sitting at an (exaggerated) diagonal in the frame rail. Now imagine putting a laser pointer on the centerline of the engine and facing it rearward on something like a LWB truck. I assume the small 1/16" out of square condition up front would put the laser point waaaaay off out back at the differential, no?
Maybe I'm overthinking it.
