I have 3 of the original run and 3 of the new run, on the original run I replace the truck with MT's, but the new run I have left alone so far. I had an issued with one of my racks of the new run with the center truck, I remove and reinstall the center truck and its working good so far. I like the new Athearn metal wheels so I not going to replace the trucks and will body mount the couplers eventually.