66 GTO 535 - Dougs 1 -7/8" round port headers / 3.5 in collectors, Pypes full 3 inch stainless system with X pipe and electronic cutouts, Race Pro mufflers, 2.5 inch trumpets
https://youtu.be/Y3Ns1lmFkhk
69 GTO RAIV 469 - Pypes 2.5 inch RA manifolds, full 2.5 inch system with X pipe, Race Pro mufflers
https://youtu.be/A4WnlgX-EV0