Earlycat, the Blue and Red Owners Manuals show the water pipes plumbed both ways in successive factory manuals. It makes engineering sense to plumb cooled water to the bottom of a radiator so the rising flow can help chase air bubbles up & out instead of fighting gravity, but who knows what logic Ford/DeTomaso followed?
I once tried both styles on a 600 mile round trip, changing configurations mid-trip at a friends garage. I found zero difference + or - in terms of stabilized running engine temp, on our car at least. YMMV.