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

Dave_J said
No.
You are given a choice to BUY one or the other at current market values of a core, long or short block. Then and only then you subtract the cost of the engine block from the $3000.
What you have left over is what you can spend for ANY parts and machining.
No parts can be from your stash. No FREE parts from friends. Every part must be open sourced 'Fair Market' Price that everyone else gets.

Seem the average price of a 318 long block runs $150. Average price of a 340 long block runs around $1000. So the 318 now gets a $850 head start.

And the thought is about not cheating.

I could sell 318willrun a $10,000 318 for $150 but that would not be honest.
His 'Bill of sale' would state "I sold 318will a 318 long block in non running condition in "AS-IS Where Is" without any warranty"

And the best would to Dyno both engines at the same shop under same conditions. Then put them in almost the same preped cars and run the 1/4 mile.