My 1954 5400 series Chevrolet COE had a Trucktor chaindrive Tandem conversion. The trailing axle actually had it's own frame rails that slid over the factory frame rails all the way under the cab. The factory axle was then mounted to this glider type frame, ahead of the tag axle, with the end results here,
http://rides.webshots.com/photo/1115990817052570246iKfhhf . There were several other companies along with Trucktor that did these conversions for Chevrolet. They were Truckstell, Truxmore, Grico, Fabco,& Thornton.
