EXCEPT Diesel engine. EXCEPT vehicles with Dual Rear Wheels. This 3.5" diameter Cat-Backâ„¢ system features the classic BORLAÂ S-Type sound with no drone inside the vehicle. The system exits thru a 5" round black chrome on T-304 stainless steel tip. Using BORLAÂ Stainless Steel Polish p# 21461 is NOT recommended with these black chrome tips. We suggest cleaning the tips with hot water and a microfiber cloth. A system with a bright chrome on T-304 stainless steel tip is also available. Add Extension Pipe 60713 For Crew Cab With Long Bed (8' 2") 172" Wheelbase vehicles. BORLAÂ Cat-Backâ„¢ and Axle-Back exhaust systems feature patented straight-through and multi-core technology designed to unleash hidden horsepower. Increased exhaust velocity adds power driving excitement fuel economy and the distinctive BORLAÂ Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium T-304 stainless steel superior to T-400 series knockoffs (such as 409) to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power and precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all BORLAÂ stands behind every system with a Million-Mile Warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand.