aFe Power 48-46008-YN Toyota Tundra Twisted Steel Header/Connection Pipe (Race) Produced +33 horsepower and +30 pounds X ft. Of torque on our in house dyno. (Tested on a 2014 Toyota tundra v8-5.7l) 1-3/4" primary tubing which merge into a 3" collector 3" diameter connection pipes mount directly to OE mounting locations Race version for increased performance and a more aggressive sound This product is not carb exempt at this time and is not legal for sale in California or use on vehicles registered with the California department of motor vehicles