It started as a 348 and not a 409 for a reason.
In 1961 Chevy produced 453 Impalas with the SS option and out of those, just 142 were produced with the 409/360HP option. It would have been virtually impossible to secure a 409 for a non-factory race care that year. The older brother, the 348, had been around since 1958 though and boring and stroking this 1960 version, took care of those extra inches.
2" tubes Fabricated by Jimmy White. Through the fenders into a side-by-side collector with an exhaust flange on the back of the collector. Pipes run behind splash pans and exit behind the running boards. Pipes are intentionally concealed so as to have the look of header only exhaust. Two nuts open the collectors.
The Pedal and all linkage pieces including the pillow blocks are all Ansen late 50's early 60's,
NOS in the package.