There's nothing to decode--all the sn is is a serial number, beginning with the "18" designating the 221 V8, and ending with the X million number that is its place in the total run of all the 221's ever built. In USA 1936's, that's the only engine and thus prefix that existed. The number contains no info on body style or color or any of that stuff that's in moder number, just V8 # ******
Thanks one of my trucks starts off *BB18- the other *18- What's the BB that is on the 1 ton, maybe because it's 1 ton
BB designates trucks, meaning in Ford useage big trucks. Pickups and panels that used the basic p***enger ch***is were commercials, not trucks. Apparently some plants sometimes put a "C" in front of some of those numbers, but that isn't general. All USA engines were numbered in a single series for each type of engine... All 221's from 1932-42 were in same number run with 18 designation, all 239's from '39-48 were in another run whether Ford, Merc, or truck. Later prefixes had a little more info to designate model year and Ford, Merc, or truck, but all had the 99 for 239 in there and were in same series of numbers.