Intake/Exhaust Gasket Help

Remflex. Always only ever Remflex. It is very much worth your while to get them and use them. Hardware and installation technique, see here and here.

The pre-'73 chokes do not work correctly when installed on the '73-up manifolds. Get one of the Electric choke kits, it'll make your life a lot easier.

160° thermostat is too cold; you're wasting gasoline and crapping up the engine oil with it. Put back the correct 180° unit—read this.