12" by 18" Fire Chief plates would be correct for this pump. Since it's a newer style A.O. Smith pump, I would suggest using a pump plate with the Circle R trademark at the bottom instead of the REG T.M. found on the earlier pump plates (from the fifties and forties). I'm not sure the exact date when these pumps were introduced, but they were used by Texaco starting in the early sixties.
I pieced together the Fire Chief pump, and I bought the porcelain panel with the original sign attached, and the sign has a revision date of 1962 on it.
Last edited by J.E.Radebaugh; Wed Nov 04 2020 02:34 PM. Reason: Add picture