Re: I found this and couldn’t figure it out
A single transverse spring was used from the early days of the T clear up through 1948. The spring mounts design changed several times from the model T thru 1948. Only the model T and model A designs had the spring directly over the axle. From then on, the spring was mounted behind the rear axle.
I can't see the suspension so I don't know how it was set up on your car. The Corvettes had a transverse spring set up but they have other members to hold the axle movement in check and it had an independent set of half shafts on both sides of the differential case. Some folks mount the spring on top with weld on perches and then add a torque arm and radius rods or multiple radius rods to hold the axle movement in check. Who ever decided that mounting things upside down, didn't think this through all that well.
This may lead to other problems such as how to drain and fill the rear axle. If the brake backing plates can be turned over or swapped then that would at least fix the brake problems.