Not to derail the thread but have a similar question of my own...
I have a 51 with the old "titled with the engine number" dilemma. Same owner had it from 53 until I bought it so it never got questioned. Engine was changed to a 235 at some point in the distant past. Not a big deal to me as long as I own it, but might create some issues if I ever need to sell out of state.
Anyone have any experience with getting title changed from engine number to body #? There has to be some kind of procedure for this at the state. And I have all kinds of documentation. The engine # on title was for a 51 half ton truck. And I have old registration docs from the 70s and such.