[OrrieG]

Usually duals on a six are used with a split manifold to enhance the sound of the opposing firing order between front and back cylinders. If you use the stock manifold, a local muffler shop can give you a quote on making up a split pipe and running duals out the back, in front of the back fenders, etc. Or you can sharpen you welding skills, buy a bunch of staight pipe, bends, etc. and make it you self. My personal experience has been they was not enough savings doing it my self vs. having the pros do it a the local hot rod muffler shop. Haven't had any done for six years but think I spent about $350 on material and installation.

Mufflers are subjective, I use Dynomax others prefer Magnaflox or ?? Best is to just go to a rod meet and listen to what folks have and find one you like and ask. Basically size determines loudness and configuration translates into how throaty, poppy or mellow they are. I have shorter 16" on my Chevelle, but put the longest (24" I think) I could on the truck.