Interesting...look a little closer, around 4000 they are the same and below 3500 the 2.5" has higher hp and torque!
My last 340 shifted at 4500 and went through the traps at 4500 at 100mph with 3.23 gears..
Yeah, at low rpm it's better with the 2.5. I just never lived there since I launched my 340 at 6800 (stick car), shifted at 7000, and went through the traps at 7400. Different world. I'll go back to the racer's forum now. Carry on :)