Have a line on a 65 Valiant, which I like the looks of. If I am able I'd rather drive it (after mods) than my Toyota Avalon. I think in order to get over 20 mpg (25 be better) I think a modern engine might be in order. Ideas? I like the 318 but not sure its the right call. What about the Dakota V6? I suppose a non Mopar engine would work but prefer to keep it less complicated. (coming from a guy who put a 5.0 Explorer motor in a Volvo) Not afraid to cut/weld/fab but again simple is better. I have owned a couple of slant sixes and wasn't impressed. Am open to hearing views on improving the slant six. Hope this isn't a all too frequent subject, should have studied first. Thanks in advance!