Stainless Long Tube Header Fits 86 to 91 BMW 320/323/325i 2.5L E30 By OBX-RS

T304 Fully Stainless Steel Dual T.I.G. welded construction for stronger hold  No instalLatitudeion instruction included in this kit, we recommend professional instalLatitudeion Manufacturer's Limited Lifetime warranty against manufacturer defects (Must fill out and return warranty card with a copy of the receipt and within 30 days of purchase date) Primaries: 1.6" OD  Port Shape: Circle  Port ID: 1.5" Collector: 2.3" Outlet: 2.0" OD Main Piping Size: N/A O2 Bung: 1 EGR: N/A Air Injection: N/A Flange Thickness: 3/8"