68 RR 4-speed 383 with factory exh manifolds mostly stock with a small vodoo cam, 915 heads, and a lot of little tricks. anyway it has a 2.5" custom X pipe exhaust going to the long body dynomax in stock spot, then flowmaster 2.5" tailpipes to tips. this setup gave me a drone between 35 and 50 MPH, used a set of the magnaflow stainless resonators with 24" total length right before the tip just like the HEMI RR's had, this got rid of the drone and also quieted it down a bit more.