Words of wisdom or gotchas for heat & factory a/c during engine rebuild 318 68 Barracuda?

Hi everyone. Getting ready to tear down the engine and wanted to know if there is anything climate control-related to watch for, either during tear down or when putting it all back together. thanks!
That depends upon how climate controlled the environment is where you will be storing the finished parts prior to assembling the engine.
The engine parts as they are upon engine disassembly are fairly impervious to rust. The same block-heads-crank-rods and and other cast iron parts will flash rust due to water condensation from temperature swings after they have been hot tanked and are super clean.
Eastwood has a dry film rust inhibitor that provides some protection, or use an oil based film for real rust protection.