General Motors:
www.gmupfitter.com
Hotline: 800-875-4742

Ford Truck Body Builders Advisory Service:
www.fleet.ford.com/truckbbas
Hotline: 877-840-4338

Cummins:
www.cummins.com
Customer Assistance 800-DIESELS (800-343-7357)

International:
www.internationaldelivers.com
Tech Central Help Line 800-448-7825

Freightliner:
www.freightlinertrucks.com