Stupid pre-buy questions

See this post (and its links) about manifold gaskets. You can fingerpaint with JB Weld if you really want to, but I've never found it necessary or beneficial. If the intake manifold is in really rough shape (which it almost certainly isn't), swap it; they're plentiful. If the exhaust manifold's sealing surface is in really rough shape the manifold is also probably warped and cracked and the heat control valve is also probably screwed up — just replace the manifold; they're available new (Yes, you can get 'em cheaper than the linked...and then you'll quickly come to wish you'd paid for the better-quality Dorman item). The '73-up type exhaust manifold is the only kind now available, which is fine; the '70-'72 choke thermostat won't work on it, but that's OK because the '70-'72 chokes are an exhaust-leaky pain in the nuts. Just get a № 1231 Electric choke kit.

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.

The transmission shift shaft seal is a common leak point and not a difficult fix; the part itself is easily bought. There is no need to replace any of the linkage parts themselves unless they are broken, which they probably are not.

Aside from the factory service manual, get the other two books in this thread.

Tune-up parts and technique suggestions in this thread.

Also read this one; most of what's in it applies equally to a '72.