I had similar setup from J.C. Whitney back in the 60's. The cable operated a flapper in the muffler that would open the muffler straight through instead of through the baffles. The mufflers basically sounded the same on or off, very loud. I thought this was cool, being a young teenager. Being a novice driver I didn't know a lot about driving. I was running down the highway and saw a State cop. Instead of pushing in the clutch and coasting past him I let off the gas. Well the popping and noise the mufflers made got the attention of the cop. He pulled me over and gave me a ticket. Since I just got the car inspected the day before the station that inspected my car and passed it got fined. Had to remove the entire exhaust system and go back to the state police barracks and have the car inspected by them. Ah! the good old days.