Kind of off topic, but one more thought. A bit of hop up equipment like Kultulz’s link shows, and a year correct overdrive transmission might be a good alternative. You’d have to change the rear gears to take advantage of it. I don’t know what rear end Ford used in those, if they got the 9” it’s simple, if they used an earlier model parts might be a problem. But dropping down to a 3.9 or 4.11 rear gives a lot more “street” performance, and the o/d maintains the highway speeds. Still uses the column shift. Those parts are out there at a reasonable price (comparing to an engine swap now). If your lucky it would be basically a bolt in (trans crossmember) and you’d only need the correct driveshaft/yoke or shorten yours.