I'm starting to daydream about my next project, which I hope will be a '55.5 to '59 and I'm looking for ideas. I don't mind a couple of extra horses but I'm more concerned about being able to afford to drive it. I have a 3sp manual w/ OD sitting in my garage and I have access to a '77 model 250 6 cyl. I'm looking for recommendations on the best 6 cyl engine to get good gas milage and any upgrades or modifications that can be made to stretch this #3+ gas as far as possible. Any help will be appreciated.