Dang. I beat my trans like a red headed stepchild and never broke it like that.
My synchros wore out and I picked up a new trans from these guys. Dropped shipped right to my house and it's been mint. They let me specify inputs and outputs, then even trimmed the output to my specified length...
Do yourself a favor and spray a glut of cavity coat or fluid film from the rear quarters in the inside down into the dog legs below the rear doors. Enough that you see it coming out of the rocker panel drains.
Better than that, my favorite, atf cut with kerosene 50/50, or used motor oil...
I'd say verify if you're hitting anything on the engine/driveline with the axle before making a decision. Hitting the bumps top is annoying but if that's all you're hitting, then it's doing its job.
I'm telling you from experience you don't, not with a 4bt, lol.
I had a single sears die hard platinum p2 in the truck for probably 5 years before I added a second to increase capacity. It was maybe 1200cca at most.
Edit: for context, I live in NC. If it's above 30*F, one good battery is all...
It's not a 24v starter.
All you need is a single battery with a good charge. Worked for me for many years.
Dual battery is nice from a capacity standpoint, not necessary to start the engine.