I was wondering if anyone knew where to find a stock exhaust diagram for a 2003 Silverado 2500HD? I was looking at my exhaust in some depth today because I recently received my long-tube headers and saw what looks like two cats. I installed a MBRP cat-back exhaust system after I bought the truck which came with two mufflers. Following the piping from the mufflers back, I see that both pipes run in to what appears to be two separate catalytic converters, from there each pipe connects up to the respective header. Is this how the stock system works on the 2500HD? I thought two cats were needed for "true duals".