Thank you for explining to me why people put in x or h pipes. For those of us that are running manifolds the only thing avaible for "tuning" would be pre-muffler pipe diameter, length to a limited degree(changing muffler location usually not much choice here) and type of muffler(s). I don't know about others but there is not quite enough room for me to run a 55 gallon drum. It would probably drone on the freeway anyway. I currently have a 2.25 pipe all the way from the engine to the outlet of the single glasspack then it drops down to 2" for the 15" tailpipe. I think there would be a small gain by going to a 2.5 pipe if it will fit. Jay 6155
