Best fluid for a l99 zf6?

[rem870ex]

Getting ready to do a fluid change on my l99 zf6 what's the best fluid to go with the ford recommend dextrose III/ mercon v or is everyone using something different thanks in advance


l99 7.3 38r zf6 4 inch rough country 20x14 fuel maverics on 33 trail grapplers

 

[psduser1]

I use scheaffer alltrans.

 

[PWRstroke_smoke]

http://www.royalpurpleconsumer.com/products/synchromax-manual-transmission-fluid/

expensive but you dont have to change fluid as often as ATF. my gear box is very quiet and smooth!