The only issue I had with the Sandersons was that the passenger side was a bit close to the frame. Everything fit well, but when the motor would 'torque' over a bit, there was this horrible vibration sound from the header hitting the frame. Fixed the problem with a grinder on the header at the point where contact was. Have about 1/4 inch clearance now and no contact with frame. As for pipes, I used the kit from Magnaflow made specifically for El Caminos. No issue with that except when installed it was too loud for my taste, so replaced muffs with longer version 20" as I recall.