Punch - Below is a screen grab from the GM Heritage Center
1935 Chevrolet Truck data PDF. Originally calls for SAE 160W for Summer and SAE 90W for Winter lubrication (with further thinning for temps below zero). Although Otto's source indicates you will need to order 4 quarts (8 pints), the actual 4 speed capacity is 6-1/2 pints. Your order will leave you with some left over for future top offs if needed.
There's tons of info on the web about the various "equivalents". One modern equivalent mentioned in an AACA (Antique Automobile Club of America) forum said the old SAE 160W is now SAE 250, which supposedly correlates to the 600W gear oil (not an SE rating) that Otto mentions above.
