Technical proper rear gear oil

I just installed a new rear pinion oil seal in my 1951 ford, I'm sure the rear has plenty of wear. Green shop manual says use SAE 90.

Car is driven in NJ with all different weather conditions, any recommendations appreciated.

 

Can't go wrong with SAE 90

 

90 weight should be just fine. Vavoline I think has in in quart bottles with a spout so us po folk can get in the rear housing without any fancy stuff.