Today, dollar for dollar, is the 318 faster than the 340 ???

go-fish said
Can we put a fork in this thing by just agreeing that they will cost EXACTLY the same except for the cost of the block. If a car had a 340 in it that needed rebuilding would a guy go buy a 318 core because they are cheaper to build? What component is more expensive for a 340 than it is for a 318?

First of all, fair market value on a 340 bare block that is known good will run you about 700-800 bucks. You now have about 2200 to buy heads, rods, crank, cam, lifters, valve springs, gaskets, intake, and carb. Good luck with that.
2nd of all, if you want a good core motor, fair market value will run ya about 1400-1500. Now you have a foundation, but I doubt it will include forged pistons. I think you are talking gaskets, cam/lifters/springs/heads redone, intake/carb and a re-ring kit.
For the "free" running 318, I'm not buying crank, rods. Good aluminum heads, cam kit, 300 dollar set of pistons, might even go standard bore. I could go on and on, but the point is I think the 318 wins the race.