I just put a chambered system on my '69. I have manifolds and smog still on the car. I love it! It's not really that loud until you step on it. I got an aluminized system from Gardner exhaust that is supposed to be an exact reproduction of the original. I took Clil's advice to not go with stainless because he said it expands when it gets hot and rattles. Be prepared to open your pocket book because I paid $938.70 for the concours package with shipping. I spoke with owner of the company when I ordered and he was very helpful and explained the system in detail. When you look at it and hear it go down the road it's worth every penny.
'69 RS SS 396 375hp L78 Convertible, M22, 3.31 posi, deluxe interior, gauges, rosewood wheel, AM-FM,fold down seat, tilt wheel, SS wheels, console mounted 8 track player, chambered exhaust