What Is A Formula 'S' Package 'Year to Year'

69 Cuda 440 said
Rocky-JS,

In 1965, the 273 High Performance did come through with a Muffler {Straight Thru Design}.

But, it was a 'hollowed out' Muffler, for low back-pressure and low-restriction.

More like a glass pack with a muffler wrapped around it. You could look straight through one.