2 Barrel Manifold

All Slant-6 intake manifolds fit all Slant-6 engines. Exhausts, too, though depending on year you might have to install a different choke thermostat. That 2bbl intake you found didn't start life on a '65 van; the 2bbl wasn't offered in North America til '77 (first year for export applications was '67; first year for marine use was '66ish).