Going to install the LD4B intake manifold and Performer 600 4-bbl carburetor on my stone stock '71 318 Dart GT (auto, 3.23:1 8 3/4" sure-grip, 2 1/4" duals with factory exhaust manifolds) soon.

Stopped by the auto parts store for a couple of things, one of which is a new thermostat. The parts guy said OE part is rated at 195*, but has 180* and 160* available. Which should I use with the combination above? (BTW I also picked up the Fel-Pro 1213 intake manifold gasket set (water crossovers blocked off)).

Any advice/direction is appreciated!