I've personally found Panteras in which the heater-hose hookups were both ways. Thats why back in the early '80s, event organizers began requiring BOTH heater hoses- the supply & return- to have positive mechanical cut-off valves when running open-track events. You just couldn't depend on one line to always be the pressurized one, and Tech Instectors didn't want to have to dig around in the cars to ascertain the routing. FWIW, it will work fine either way, as will the arrangement of the radiator hoses up front.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.