Has anyone used Amsoil synthetic Transmission lube 75W-90 GL-4 in their 1969 4 speed?

Just one comment on oils, anyone remember the graphite oils? I think it was Mobil that started it. Used it in my 305 chev...instant valve tick. Drained it, flushed it 2 times and went back to regular Valvaline...It stopped ticking after a few oil changes and 4 months. I still have a qt or two around. Quaker State had a problem in the early 80's and paid for some rebuilds. I seem to remember being told that you never use atf in a 833. I also heard the guys that ran fast used it. That was from the 70's though and trans oils are alot better now. By the way, I used 90 wt in my 833, never destroyed one but wore out the synchros!:-D