The 1964 GMC v6 truck uses 5.5 quarts of oil or 6 if that of the oil filter is included.
To change the transmission fluid on a 1964 V6 GMC truck, you will need the manufacturer manual.
5 quarts
8 quarts
7 quarts 5w20
5.7 quarts
12 quarts 15w40
Using a Sierra Classic 1500 Series Truck I came up with 6.1 quarts
3,6 litters
5
With filter it is approximately 6 U.S. quarts.
About 10,000 pounds.
# go to your local car and truck store and ask them