Today, dollar for dollar, is the 318 faster than the 340 ???
Being as I have examples of both engines at my disposal, I pick the 340. And, more to the point, I wouldn't sink the $$ or time into the 318, if I could sink money and time into a 340. Why? return on investment, I don't mean selling the 340,( although market value of a 340 is a plus) I mean the money/time sank in would return more horsepower out of the 340, and the 340 just comes with beefier better better internals at the time of the initial investment.