Gas price going up // Rethinking the new project car

How light could you get a 64 Dart or Valiant using an aluminum OD and bell housing , aluminum radiator, keep the 7.25 but run 3.23s or 3.55s , aluminum slots etc...? Base curb weight is 2550ish lbs and all the alloy parts would shave 200 off maybe ?
Would a 318 with aluminum heads and intake be close to a slant in weight ?
Maybe fuel injection ?


Seems like you could get into the 30s for mpg with a max effort efficiency build and still have a fun car .