Well the 440 wasn't an option in a 74, but a lot of people like to swap them in as they were the big engine (aside from the Hemi). Doesn't look too bad. Be a fun cruise night/driver but would take a lot to turn into a show car (if that was your intention).
Well done rest-mods do have some value, especially if you do a lot of the popular upgrades (handling, disc brakes, etc).
My advice, get it running good, and go cruising with dad/wrench on it with dad, the memories will be worth more than the car ever will be