Maybe a spread bore would work best for you. I think they sell them in a 700 - 750 and that would work good too. Running on the small primarys when your foot is out of it.
I agree, if he wants more towards mileage. But the difference between the small DP and a spread bore for mileage IMO on a 318 will be minimal, so why not go with the better performance? Either will work well, though. I think the little 625 Street Demon would turn it on too.
