Please tap Read More for more details of the product. For F/A/B/X-body Chevy/GM cars with 283-400 SBC V8. Shorty design for power gain from idle to mid-range RPM. Fully mandrel bent tubes made of 16-gauge mild steel. Head flanges laser-cut from 5/16-inch thick steel plates. Flanges flattened by hydraulic press for precise and leak-free seal. …