Automatic to manual conversion.

360s can put out a lotta torque, and torque busts stuff.
The budget way is an A833. These are practically indestructible to a 360
The best way,IMO, is a 5-speed. This lets you run a performance rear gear, which allows your engine to spool up faster, and hopefully your zero to 60 can be much improved; all while maintaining hiway driveability.
And the worst for performance,IMO again, is the Mopar od box; for two reasons. Firstly, the splits are engineered for a low performance low-rpm engine, and Secondly, the od gears are weak and if you forget that you are really shifting a 3+1 then zing! .. there goes another one.I've been shifting A833s for so many decades, I found the transition to 3+1 extremely difficult; so after I blew up the third one,I realized my limitation,lol,and got something else.
My favorite is the Commando box with the 3.09 low in it, which lets me run 3.55s on the hiway; yet it takes off like it had 4.10s.
If I had money tho, I'd get a 5-speed. A big freaking HD one, cuz I'm done stocking spares and replacement parts.

As to the aluminum cases, I bushed the front cluster-pin hole and had no trouble with it