1) 1-5-3-6-2-4 counting from the front (water pump) end (thanks to 54TOW, the incorrect digit has been removed)

2) Group 1 battery size? ( here are dimensions ) Chevrolet used Group-1 6V batteries through 1954.

3) What year engine do you have? When in doubt, use 30 weight oil. (The 38 and 41 Shop Manuals say 20 weight)

4) 1941 Shop Manual is closest to your year.
(1938 Shop Manual)