Permatex #2 and perhaps High-Tack (or Indian Head, similar product), and Permatex Aviation Sealer, is all you need for these old trucks. They were recommended back when they were new, and really, nothing else that's come out is really any better. Don't use the RTV on the gaskets, though. That stuff is intended to replace gaskets, not be a sealer for them. Most cases, using it on a gasket will make it leak worse. Not saying RTV doesn't have its place, but used a s a gasket sealer is not one of them.
