Headers are 2x32 with a 3.5 x 15 collector. They are probably a little small for this engine. I had them built years ago for my 650 hp engine. I hate to go buy another set for this engine so I'm probably leaving some power on the table.

I've run both the 440-3X and the Super Victor and the power curves look basically the same. SV was 715 ft-lbs at 5500 and 830 hp at 6700 rpm. The 440-3X was 715 ft-lbs at 5500 with 816 hp at 6700 rpm.