Our Greatplains drills were about '88 and 90 something and they had Uniroyals that looked like BFGs.  I didn't realize (or had forgotten) that there was a connection there.  The BFG plant was right down in OK so you'd think I would have a better idea then I do. 

Neighbor's 2640 had BFG 11L15s on it.  Those were very nice looking 3 rib tires.  Brothers ordered a pair for our 4010 and they were crap...the tubeless tires had big meaty looking treat on them, but the tube type looked like innertubes.