I really like a flattie....that being said, part of your decision depends on your skill set. If you're able to tear down the flathead to replace gaskets and seals, maybe throw in a little bit of extra work to freshen up the engine (rings, possibly bearings, and a valve job if they need it). I've always been amazed at how well old Ford engines will run even when the clearances are way out of tolerance. A minor overhaul could breathe some new life into your engine. How much do you drive your truck?

Dan