Shop MagnaFlow Performance Exhaust Systems for the 1965 Pontiac GTO, including exhaust systems for select engines, trims, and configurations. Engineered to produce MagnaFlow's deep signature exhaust sound, these systems feature premium materials and easy direct-fit installation. 1965 Pontiac GTO exhaust options include 2.5-inch and 3-inch main piping diameters; polished exhaust tip finishes; multiple and dual split rear behind rear tires exit styles. Use Shop by Vehicle to find the system for your GTO.