Hmmmm- - - - -interesting! One thing in its favor is that a small block V8 will drop in onto those engine mounts and bellhousing without much if any massaging. If you're not into belly button (Everybody's got one!) V8's, a 292 big six will fit with a slight reposition job on the passenger's side front motor mount. The 230 might be a little on the lightweight side, power-wise, for the rest of the truck you've got there!
Jerry