I just bought a 1969 Dart GT, with a 180 horsepower 273/2 barrel. I would be very happy with a 5.2 with bolt on upgrades.
300 horsepower 5.2 is easy to achieve with factory heads.
Remember Rusty rat rods guide to hotrod bliss? We could be satisfied without having bragging rights and enjoy our cars.
I will be just as happy running a 13.5, which will put a grin on your face and have money for dinner.
Even if we had a $1,000 dollar challenge, I could do a 5.2 with bolt on parts..ie headers, cam, intake and carb.
Oregon cams, now charges $179.00 to regrind your core. Still money way ahead. It would be close if not better than '73 340.