As the trans is a side loader and has the shorter input shaft it is most likely a passenger car unit, pre-55. If this is the case and you had a F-100 3 speed
non-overdrive trans you should be able to adapt the overdrive to it, needs an extra hole in the trans case for the reverse lock out shaft. By 55 there were different trans gears sets depending on the motor it originally came with (F-100).
Really? I was under the impression you couldn't mate the tail shaft to the non OD trans. There's a 3 sp side load with bell in my favorite junkyard.