Type F fluid in 727

ATF+4 is what I was told to use for better lubrication. I drive mine on the street with a 5500 8" dia. stall and 456-1's. 29's. Yes it does get hot but no problems yet. Shift light set at 8000. Diesel internals, Drum , planetary's and bolt in sprag for strength. I think my weak link is the 8 3/4 and shaft. Was gona do a 9" , but going to a Dana. Want to stay mopar