Tranny swap from auto to 3 or 4 speed

I once worked with a guy that needed a low buck reliable car. What he found was a late 70's Volare wagon that had been used by a delivery service. Although only 3-4 yrs old at the time, it was showing about 100,000 on the odometer. Problem was it ran like sh**. He asked if I could fix it and I said "Yeah!" He bought it for about $800 and I drove it home. It would not get over 40 MPH on the Interstate. I kept it for about 10 days, had the head rebuilt, (2 burned exhaust valves), rebuilt thefroze-up 2 bbl carb, did the brakes, shocks, etc. When done, it was a very enjoyable smooth running car. And I was jealous. Every time I saw him in the halls at work for awhile, he'd stop and shake my hand and thank me profusely.

Anyway, the whole point is that it was a 225 /6 with a floor mounted 4 speed overdrive. (This was the aluminum case tranny where Chrysler flopped some gears around inside a 4 speed and switched one of the shifter arms.) So a Volare, Aspen, mid 70's Dart would be a source for a tranny and bellhousing. I see these trannies at all the large Mopar swap meets. The Dart Lites and Plymouth Feather Dusters with that trans had highway mileage into the 30's. If it was me, I'd go with the overdrive as long as you're going through all that work.