Yeah, you really don't want to use 308s on a 318 with a stock, or near stock shortblock- you lose a full point or better on your CR, and most 'teeners can't afford that.
Of course, it works the other way, too- 302s on a stock 360 shortblock gives you a nice CR bump, and with a mild street cam you'll never notice the smaller valves/ports. You may even see an uptick in low-end response.
