I raced a 4 speed car for several years in NHRA stock class, one slick shifted tranny until it burred up real bad and then switch to Pro shifted by Nash and Liberty.
Back then in the mid 1970s the Mopar drag race engineers recommended using straight ATF, that work fine
I would make around 40 passes on the car and remove the tranny to replace the clutch disc and pressure plate and look inside the tranny to see if I would have to take it apart to dress up the sliders and engagement lugs or not.
I did that deal for 2 1/2 years and then sold that car and went back to racing automatic cars, my wife liked that a bunch better as I had to have her help me on the tranny R&R with a floor jack in our driveway at night after work
She bought me a Sears tranny jack one year for Christmas