These are standard medium or heavy duty truck parts, depending on your specific chassis and who made it. Who supplied that front axle to the truck manufacturer - Meritor, Freightliner Alliance? Have that information available and start with a local business that suppiles parts for truck repairs. Truck dealers, truck parts suppliers, NAPA truck Parts, etc.
'07 Winnebago Journey 34H, ISB-02, MH2500
Toad - '08 Ford Taurus X
Blue Ox, Aventa
US Gear UBS