Hey folks, I got a 46 WC 1/2 ton, and I'm wanting to know how to tell what year the engine in it was made. I'm thinking it's a 230, but the serial number was filed off for some reason. I heard the year it was made should be stamped below the distributor, and on this engine it says A1 then right below that it has 6 5 7. So would this engine have been made in June of 57? Any help is appreciated, thanks.