And for god's sake don't put that ATF+4 shift in the trans.
Ran +4 in my built 47RE. I even run it it my 904 in the race car
I'm other way , I don't run + anything in my built 47RE .
Not sure why we would use hi friction clutches, eliminate things that soften the shift and make everything apply quicker, add clutches to increase surface area, turn up the pressure, do everything more aggressively, and then put slippery trans fluid in it that is designed to make it shift smooth and soft, so grandma doesn't complain about feeling the gear change.
I went from Type FA to a premium synthetic ATF made for late model passenger cars in my two speed. A unit that would go plenty of runs and have the clutches look and mic like brand new . The result was black streaks on high gear clutches and steels from slippage on apply.