On one truck pull engine we built (a MOPAR 440) the tuned length of the header pipes we custom built were 8 feet long, and the ones for the 2nd, 3rd, and 4th. cylinders on each bank extended back into the 6" collector to keep the tuned length the same on all the cylinders. We were building for maximum low end torque, but the engine still maxed out at 714 HP at 6500 RPM on one Quadrajet carburetor and gasoline. The class we were running didn't allow racing fuel or more than one carburetor.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!