SM465 Gear Oil Question

[Desert_Eagle02]

Hey guys, I'm going to change the gear oil in my SM465 trans and my NP205 t-case. I picked up 7 quarts of Valvoline High Performance 80W-90 gear oil. That's what I read that they took after doing a bit of research.

Anyway looking at the back of the bottle it says
"Designed for use in non-synchronized manual transmissions where GL-5 is specified and for hypoid differentials where API GL-4 or GL-5 is specified."

"Differential: API Service GL-4, GL-5
Non-Synchronized Manual Transmission: API Service GL-5"

So can I use it in my SM465 since it is synchronized? Or should I pick up something else?

Thanks