Carb Issues

It's entirely possible the carb you have will work fine on your car. The determining factor is whether or not it has a spark advance port and nipple.

The '70-'72 cars use a 3-year-only choke thermostat setup, with a stamped steel cup bolted over an open hole in the manifold leading directly into the exhaust crossover passage. There's a gasket between the cup and the manifold. When (not "if") the heat crossover gets clogged with carbon, the choke stops working correctly (stays closed much too long because the thermostat bolted into the cup doesn't get hot enough to open). If your blockoff plate is not leaking exhaust, leave it be. Put in one of the electric choke kits which does not care whether the crossover is clogged and will not require disturbing the blockoff plate seal/gasket to install. The link lists the P/Ns for slant-6 applications, but contact the source for your V8 application. It is of no consequence as far as choke selection that you are using a '79 carburetor on your '72 engine; the same choke thermostat will hook up just fine.