I'm just worried that it's been so long since I did this stuff daily that I've forgotten something and will p*** somebody off with garbage info. It's easier when you're actually under the hood! Yes, the entire distributor will be replaced, and the coil is part of the new cap. The whole shebang comes out with a 9/16 bolt that retains the distributor via a bracket on the manifold. I THINK (see above disclaimer) that they all interchange on s.b. chevy's, gear and all - I've swapped dozens so far, but as the oil pump is driven from the distributor base, maybe one of the other guys here can confirm that? Everything that the ignition needs will be on the new distributor including the coil. There is one wire to make it all go marked B+, and an available tach lead. They're virtually maintenence free. As for crankcase venting: I don't THINK the modern PCV valve came in until about '72, so I'm not actually sure how it was done before then, but somehow the crankcase must be vented to atmospheric pressure or vacuum. If it's not, the blowby (gasses and pressure from combustion escaping past the rings) will pressurize the crankcase and can force oil past seals. You may simply have a hose running from a breather cap to the air cleaner if pre P.C.V. Interestingly, the PCV valve, because it uses engine vacuum to evacuate the crankcase does a better job of clearing out corrosive gases (I think it's sulfur dioxide that mixes with the oil to form sulfuric acid and eats the bearings) so it's better for your engine in the long run.
