[chewychevy67]

I got a set of Nos left and right dual exhaust mufflers parts 3861811 and 3861812. They have 2.5" inlets and 2.0" outlets. I think everything gm put out had 2.0" outlets in these years. They are correct for 64 327 with high performance (not special high performance). The engine I'm using is a 64 327 300hp so I may use them. My original truck motor will stay on the stand. Not too much original about this truck any more anyways.