Nice job and a nice memory for you to have, of your old pony car ! I have done the same. I have a 1/18th scale model VW Beetle (my first car) that I prominently display on a shelf. Always nice memories generated whenever I look at it.
I recall reading (Hemmings I think) about a guy who bought a new Mustang similar to yours and ordered the 351 Cleveland V8 with a 4 barrel and a 4 speed and a final drive gear ratio somewhere around a 2.73 . He also put on some powerful driving lights on the bumper....that could be flicked on/off...for when conditions were right...ie; no traffic @ night. I could be wrong and probably am,
but if memory serves me, he might have also installed a Volvo driver's seat for long distance travel comfort.
If I recall, he lived in NYC and had a close relative of his, that he liked to visit regularly, somewhere out west....Montana, Wyoming, ? was this was the reason that he had equipped the car with that relatively high speed @ low rpm final drive ratio, Cleveland 351 engine, 4 speed manual, etc. as he liked to make good time, once he got to the less traveled western states.
Believe the story said he put somewhere in the neighbourhood of around 400,000 miles over many years, with little trouble.