Clarification on 73+ brakes

Yes, can use distribution block. 1968 should have separate F & R circuits, both w/ 3/16" tubing which matches any later MC's. 1966 and earlier cars can too, but more fittings needed. Yours also probably has an "imbalance switch", which you can keep (my 1969 Dart did). Just add an adjustable proportioning valve in the rear brake tubing and adjust so the fronts skid just before the rears in a wet parking lot. Might want to plumb it up higher, out of the mud & rust zone.