School me on 340 exhaust manifolds

"After all this, I may have to go headers for now until the Canadian dollar gets higher or I find a better deal."

An easier option (in terms of labor) would be a non-date correct driver quality set. Then when you get the ones you really want, its a relatively easy swap and the exhaust needs no further mods. With a little patience and finese I can get the manifolds in and out without removing or loosening anything else. Manual brakes, manual steering in my car, so I can't be sure this will be true on a p/b car, but something to think about.