Stick with the stock setup if possible. Duals make nice eye candy and add a little performance at the top end of the RPM range, but the carburetor really needs that manifold heat to run right, especially during warm-up. Be aware that the position and angle of the outlet changed a time or two, so some tweaking of the exhaust pipe might be necessary, and/or a modification of throttle linkage, depending on which exhaust manifold you end up with.
Jerry
