Thanks for the input - yes those are mpg for imperial gallon, not US. If I was to stroke out the 5.9 magnum, I would probably look at headers and different exhaust . . . keeping the 5.9 magnum, relatively stock would certainly be better than the LA, I was thinking . . . and of course keep the original engine tucked away . . .

The MPG concern isn't so much for what it gets, rather, how many miles I can go between fill ups, as the Duster has a small tank !!!