I recently repainted my 1 ton panel. I was topcoating older paint and it took almost 3 quarts for the fenders and the longer than 1/2 ton running boards. The body, which is longer than yours, took about 2.5 gal of a single stage urethane and I really need another coat on the roof. This was just a backyard paint job so you might bear that in mind and the 1 ton IS alot bigger than the 1/2.
I really think that 1 gal will be running pretty close to the wire, Don
