Shorty design for power gain from idle to mid-range RPM. Gains 10HP and 10 lb-ft torque. Mitered merge collectors to maximize exhaust velocity and scavenging. Fully mandrel bent tubes made of 16-gauge, 409 stainless steel. Head flanges laser-cut from 3/8-inch thick steel plates. Flanges flattened by hydraulic press for precise and leak-free seal. Flanges chrome plated for corrosion resistance. All joints TIG welded for resistance against cracking and wearin.