OK, kinda expected that...lol
if I were to run my 318 against your 340 I would want them on a fair / even playing field.
I do not know enough about the tech specs of each engine to compair.
boring, stroke, heads, etc.
put 340/360 heads on, after market heads, cam etc.
I will drive this on the road, but if I want to run someone I want to know I have a good chance at beating them...