I know most people run pennzoil, amsoil, or redline. I’ve ran royal purple for the past few years but I decided to give the valvoline brand a shot. The part numbers for mopar are on the bottle.

Been driving for 8k so far and been good with daily driving and towing, trans temp seems be run the same as royal purple. Shifts smooth. Don’t know how it compares in the cold yet, but I don’t think it’ll be a problem. 
 

Valvoline MTF is what I want to use next but can't my transmission re builder suggest against his because is not a synthetic. 

It seemed thinner like a synthetic when I put it in. was thinking about that also before I bought it how I couldn’t find that anywhere on it or reading about it online. 

Mobil 50 SAE I'm running is a synthetic and it is a GL-4 gear lube which will protect all syncro's. It thick like 90 weight gear lube but rated for all Eaton Fuller 10 speeds in commercial applications. I prefer a thicker gear lube for transmission that is towing that a thin one that might give good shift performance.