Review on Gibson 421887 Superflow Stainless Muffler by Broderick Shetler

love Gibson exhaust products. It had a flyback system on the Chev Astro. More power and faster acceleration. Much less exhaust brakes. The temperature of the catalytic exhaust gases dropped by 100-150 degrees. The exhaust runs cooler. There's no difference in miles per gallon, but there is a difference in performance. I highly recommend Gibson.