I'm not one of the numbers gurus, but that's a tough one.
Where did the number come from? Paperwork? Door Post? Frame? I know the TF trucks drop the leading "3A" (series and model) from the frame stamp.
Still, to only have five digits at the end of your VIN eliminates a lot of things... like any Chevy truck VIN after 1953. Also don't think it is an engine serial. Throw in the random letter placement - well, it's beyond my feeble abilities.
