Stainless Works 2015+ Ford GT350 Headers 1-7/8in Primaries High-Flow Cats 3in CollectorsImprove the sound and performance on your Ford GT350 with premium headers from Stainless Works. American Made and designed for the 2015+ Shelby GT350 & GT350R 5. 2L, these headers feature 1 7 8" primary tubes that are CNC mandrel bent to increase air flow, and engineered to create power. These headers come with 3" slip fit collectors, as well as high flow catalytic converters that flow into lead pipes swedged down to 2 1 2", merging into an easy