Thank you both. Appreciate the center to center bolt hole measurements.
I was considering buying a 1970 slant 6 Dart a while back, but passed.
With those measurements and pics from Schumacher in hand, I should be able select a correct K-frame and to convert a slant-6 to V8 if and when I run into a situation where the slant-6 car isn't too rusty. Hard on the East Coast.