Inliners International Forums General Discussion Engines Exhaust size effect - is bigger always better?

Here is mine from the 65 Chevelle wagon.
Hooker long tube headers, 2 1/4 out the Y pipe, 2.5 muffler input and 3.0 tailpipe. It pulls at all rpms with a mild cam and 250, 5 speed and 2.56 gears. No overdrive.
Duals to a single is the way to go.