engine/trans vibration

If the headers are close to the frame, once the RPMs increase and the motor twists it might be making contact with the frame. I thought it was the driveshaft at first because it was new after I put in a Gear Vendors. The shaft had .040 runout. The drive train shop made a new, new drive shaft and it had .007 runout but the vibration was still there. I saw where the pipe just after the collector was close so I smacked it with a hammer, problem solved. I did cut the pipe and welded on a new collector on it.