[68 P.O.S.]

Welcome to the board. I'm not too far from you. Adding dual exhaust is a great idea. As suggested, add a H-pipe or a X-pipe. Don't listen to the nay sayers about headers. The only time you'll have problems is if you buy crap headers. Good quality headers won't leak any more than a set of stock manifolds will. Get a set of Doug's or Doug Thorley Tri-Y headers as they're meant for low rpm where you'll be driving at. They're spendy, but well worth it. However, I agree that you should stick with the manifolds at the moment and just add the duals. Get to know the truck for awhile and save for good headers.