Dart Restoration
It's nice to see "kids" (I'm 58) still appreciating the classic muscle cars.
I had a 64 Dart GT when I was 17 (actually my dad's) Wasnt until 69 that I got my first new car 69 Dart GT 318. Car ran in the 14's with a 4 bbl, 4 spd and 4:10's on Goodyear F70 14 polyglas tires!
A ncie small block 340 or 360 crate would do real well. Much easier to keep tuned and less of a headache trying to shoe horn it in there.
In any event, whatever you do to it, make sure you DRIVE it. None of them look good laying around in a garqage.