What is the best trans fluid these days for an A-727

Thanks pettybludart , not trying to be difficult , always the same when it come to syn vs dino fluids . Are you still having the seal leak on the trans ? Is the syn fluid the reason given for the leak ? I had 2 rebuilds leak from 1 front and one rear seal ,but they were using dino fluid . I grenaded a few 904's in my day , yours looks worse than any I blew up .
Is your trans guy saying the syn fluid was a contributing factor ? With the price of a rebuild don't want to be putting the wrong fluid in , so trying to get as many opinions as possible .