Take a center punch, and evenly punch several dents all around the ID of the hub. Then drive the race into the hub, that will usually stop it. Locktite also makes a paste called something like "bearing lock" or something, and you can also smear some of that in the hub area and that will stop it from spinning. I am assuming it fits pretty well, just a tiny bit loose. If it's really bad, then yes you will need a new hub.
Here's some junkyards in North Carolina that have some dana 50 frontends for sale. Maybe they will sell you a hub off of one.
1996
Front Axle Assy.
Ford Truck 250 4.10 4600 **** 50 WBM06 $800 Marsh Auto Parts USA-NC(Siler-City) E-mail 1-800-742-4715
1994
Front Axle Assy.
Ford Truck 250 4.10R.4600LB 06061 $600 Marsh Auto Parts USA-NC(Siler-City) E-mail 1-800-742-4715
1996
Front Axle Assy.
Ford Truck 250 4.10R 11580 $600 Marsh Auto Parts USA-NC(Siler-City) E-mail 1-800-742-4715
1993
Front Axle Assy.
Ford Truck F250 not Super Duty Center carrier only 135,000 00002099 $288 Foil's Auto Recycling LLC. - - ARAPro USA-NC(Harrisburg) E-mail 704-455-4300
1989
Front Axle Assy.
Ford Truck 250 4.10,CENTER CHUNK,DROVE,EDIT 440 G80935 $200 S & J Motor Company, Inc. of Yadkin USA-NC(Yadkinville) Request_Quote 1-336-961-2228 Request_Insurance_Quote
1990
Front Axle Assy.
Ford Truck F250 410 RATIO 139,000 A 1249L $Call Chapman's Automotive USA-NC(Hillsborough) E-mail 919-732-3410 / 800-672-2524
1994
Front Axle Assy.
Ford Truck F250 XL,5.8,ATOD,RWD AA0557 $Call East Coast Used Parts USA-NC(Clarendon) Request_Quote 877-914-4800 Request_Insurance_Quote