I recently replaced a bad muffler on my 53 (1960 235) with an 18" glasspack. Has anyone experienced any flow issues with these? Mine sounds horrible at idle, almost like its missing..just a rough idle. No obvious leaks in the pipe, I welded everything, and the engine sounds smooth when your standing over it. I even went as far as to replace the plugs and wires, swaped out the carb. same issue.
plenty of fuel to the carb too.

Chris



1953 Chevrolet 3100