Yes, but you are talking about a modified 318, adding parts that a 340 comes with stock. I believe what you are saying as it makes sense you could work 340 parts and specs into a 318, I am saying you are putting alot of effort into turning a 318 into a 340 when all you had to do is start with a 340 or A 360.It comes down to economics really I wouldn't spend that $$$ on a 318 if I really wanted a 340. I would fork over the cash for a 340 and start with that as a build, that or a 360. The thousandths of an inch in the bore does matter because it is displacement and air flow, the blocks can only safely be punched out so big, each bit of airflow through each cylinder adds up. It has been a long time standard that with a small block you want a 4 inch bore, you cant get there with a 318. I know its semantics but to each their own. Tis is almost like arguing 883-1200 in the Sportster world :)