there was a 1965 or 66 A100 pickup up on one of those used car lot "angle iron" ramps many, many [and many more] years ago on the way to work.
i stopped to look, and it had a poly 318/727 combo.
first thing i thought of was a big block swap.
after doing some measuring, i came to the conclusion, a 383 [or 400] would fit great, requiring only motor mount biscuits and swapping the transmission guts into a big block case. [it had a shorty tail shaft and a sliding yoke like a 4 wheel drive would have]
i can't remember what the asking price was, but the body was pretty sound, while the interior was bare with ratty seat covers.
one of those things one wishes he would have bought, but on the other hand, i can't seem to finish what projects i have as it is.