How much were you able to drive the car before the transmission went south?
The stock transmission and axle gear ratios will put you at approx 3000 rpm at 70 mph. A lower rpm at that speed will feel much more comfortable. Even around town with my Fordomatic the engine is wound up more than I'd prefer.
If you'd like to do a fair amount of hiway driving you might prefer an AOD swap, for the overdrive.
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basic AOD info...
https://en.wikipedia.org/wiki/Ford_AOD_transmission
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