ran my footbrake launched Chevelle with a cast iron oval port headed 468 for many years with both a rectangular Performer RPM Air Gap and Holley Strip Dominator intake.
Made at least 725HP@ 6300 and 600+ ft./lbs. torque @ 5100 RPM! Some say at least 750HP!!
Ran 10.07 @ 131 through a full exhaust system in my nearly 3900 lb. Chevelle as well it ran quicker and faster than EVERY 454, 496, 502, GM's 720HP 572 and most 540's in a similar Chevelle here in Division 1 brackets!
http://s381.photobucket.com/albums/o...current=10.flv