Brad By cutting off the "Y" and routing a second system you get to save money at that point in time. On the other hand you now have a use system on one side and the new on the other ( kind of like buying one shoe lace at a time ). The "H" or cross over pipe is a step above the pair of straight pipes running from each side of the engine to the rear bumper. The effect of the "H" system is best at idle to about 1,800 rpm's. The cross over pipe should be the same diameter as the two exhaust pipes and as said, as close as possible to the engine ( the space / gap between the engine and the transmission is most offended used ). The best system is the "X" system. It starts to help the engine from idle in a manner above the "H" and continues to red-line. Please have your shop guy ask or read the tech info on the "X" system. Rodger & Gabby Colo Spgs '47 De Soto Custom w/Fluid Drive & passenger door mounted swamp cooler '63 Le Baron w/F-Sweep trunk lid & std A/C * '66 Le Baron w/dual A/C & reverbed AM/FM * * with the above mentioned exhaust systems and a trailer hitch connected to a ''70 AirStream 27' International