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

Acknowledging the parameters of the test, i think it simply comes down to the budget.
$1000 budget, free 318 vs $1000core 340, 318 clear winner
$6000 budget, 340 clear winner.
$3000 budget, i can see it going either way, depending on a lot of factors. I would probably lean toward a 318 with good aftermarket aluminum heads over a 340 with stockers.