best auto trans fluid

Valvoline Maxlife "Multi-Vehicle" ATF. Full syn, great additive package, comes in big bottles, reasonably cheap. Or Mopar ATF+4 spec which is pretty close to the same stuff. If you are not shifting on the track, anything that won't foam out will work fine. A synthetic will pump a little easier, potentially using less power.

Back in the day, guys at my local track liked the A230/A233 3-speed manuals. Light, simple, and basically free.