67 Dart Disc Conversion brake hose too short

If you mount the calipers to the rear then get the correct calipers. Late model FMJ cars had the calipers hung to the rear. Those calipers have the hose at the bottom and the bleeder at the top. I've never seen a factory hose that works correctly with rear hung calipers but custom hoses are easy to buy. Goodridge has a whole line of DOT brake hoses or any good local hose shop can build rubber lines and pressure check them.