Ultimate daily-driver Gen II A Body to build

My buddy is looking at a similar idea with an 70-72 dart. Lighten car as much as possible (fiberglass body panels,8.25, etc) fuel injection,turbo, overdrive trans, lower chin spoiler,light weight wheels/tires, etc. He is shooting for 35mpg with cars weight in the 2600lbs range. I think if he builds/balances motor with a light rotating assembly he can do it. Still in debate on 170,198,225ci.