Thorley headers 73-87 CHVY / GMC TRI Y BB

Thorley headers are designed to outflow your stock exhaust manifolds. They are designed with an emphasis on maximum low and mid range torque, while making ample horsepower throughout the RPM range. The Tri-Y 4:2:1 configuration builds the most power in the middle rpm range, which is great for towing and steep grades. To make these headers last, Thorley made them out of durable 14-gauge mild steel with 3/8 in. thick flanges and 5/16 in. collector rings. To prevent leaks, these headers have an O-ring welded into the flange, in addition to the high-temperature gasket provided. Unless otherwise noted, these headers are designed to fit the vehicle as it came from the manufacturer. This includes components like cylinder heads, chassis, steering, motor mounts, body mounts and bushings, etc. If your vehicle is using aftermarket components, parts from other applications, or custom altered parts, then it is the installer's responsibility to verify fitment.
Tri-Y one-piece
Steel
Silver Ceramic Coated
14-gauge