Half Exhuast

My ideal exhaust would be 6-1 header or an early series 1 exhaust manifold with 2 1/2 pipe on a turbo muffler. I would place an automatic cut-out just behind or equal with the tranny for those times I need the extra HP and sound. As of right now I have a stock exhaust manifold with 1 1/2 pipe and no muffler. Its loud at idle and crazy loud when getting on it. My 76 is labeled a non-catalytic car.