4 speed transmition oil

I use 80-90 also. ATF is ok in tranies than run in very cold conditions, but synthetic is better then also. Since we don't drive our cars in the cold too much, just stick with the 80-90. B&M used to sell "Slick-Shift", is it still around in some form?

"Slick-Shift" isn't anything more than expensive Type F. (So I've been told).
I use ATF in mine. Seems to work pretty good for me.