Is it slick shifted or Pro shifted?
Not face plated, correct?
I used type F ATF in my old 4 speed drag race NHRA stocker with both types of gears in it
I did take it out and inspect it after 40 runs or so due to the clutches we had back then, mid 1970s only lasting around 40 runs
I would remove and dress up the 4th and 3rd gears and its slider after 80 runs and replace them after 150 + runs and have them redone on the engagement lugs
I quit drag racing 4 speeds after 2 1/2 yrs of doing that