Jason, the manifold that has not been cut will be stronger and I believe you will get about the same "Sweet-six" dual exhaust sound. I'd stick with 2" pipes for both of your duals, though. I had the same set-up on my '65 Chevy pickup and it would give you goose bumps when you wound out to about 2,000-3,000 RPM. I used dual 2" pipes from the manifold outlets all the way out the back, with dual Smitty's. Cherry bombs will probably be louder.
