Stainless Works 2008-09 Pontiac G8 GT Headers 2in Primaries 3in Leads Performance Connect w/HF Cats2008 09 Pontiac G8 GT 6. 0L Headers. All tubes are CNC mandrel bent for optimal flow. Made from 304 stainless steel for maximum corrosion resistance. Starting with a CNC cut 3 8" thick flanges into 2" diameter primaries, Flow into 3" slip fit collectors with a merge spike, then fitting onto a set of 3" high flow catalytic converters then flows into a set of Performance connection leads with 3" outlets and 1 2" wire hangers welded on to fit into the