1971 slant 6 manifold gaskets

Another thing: if you still have a 1971 ('70-'72) exhaust manifold, save yourself a bunch of hassle and just replace it (get a good one)). The '70-'72 exhaust manifold has an open-hole type choke stove, with a stainless steel cup gasketted in. That junction is leak-prone, and the gasket is unavailable. Putting on a new exhaust manifold will solve the leakage problem and get rid of that factory-built exhaust leak at the top of the choke stove. You'll need a different choke thermostat, so save yourself some more hassle and get a № 1231 electric choke kit.