Not to mention the bolt pattern on the wheels being the big ford pattern. That F-150 has offset beams which wouldn't work too easy. Cboy made them work, but on a home built with custom rails and ran no hood or fenders.
The stock suspension will hold the 300 I6 easy with some custom mounts. Could even find a column shift 3spd and hook it up to the stock column. No reason to over complicate things.