Hay Ken CT " size matters " the tail pipe on youi 36 is ? 1-3/4 or all stock 1-1/2, and is the engine all stock original ?? here again size matters. if we add a built engine, with hi comp heads, the sound changes, and now lets add a super HOT CAM , the timing of the exhast valve, closing will make difference, tone/or noise... are we going to push all that out ...what size pipe ?? If we go a 2" pipe, will we get some or none at all back-pressure, some is needed, or is it just an ECOE-CHAMBER ?? As for the open dump tubes at the headers, what the old timer was telling you, a cold draft of air,when you shut it down, up that open port can or will warp the open valve, standing wide open, and being super hot, ...If we keep talking we can find another can of worms to open, and where is; JM ..35 .. SEDAN ??? .. he's all about open tubes... OLD...BILL