Haha, what if?
Chances are if IH wouldn't have had to sell of CC there would be no such takeover by Tenneco, and the evolution that would have been CNH to swallow it up. Providing there wouldn't have been another strike and that the TRX program would have given worldwide commonality back to Harvester, saving quite a bit of cost. IHC would have likely still bought the Steiger plant in Fargo. It may have also been in a position to swallow up Ford New Holland in 1991 before Fiat did (and maybe leverage the distance and product between Steiger in Fargo and Versatile in Winnipeg, as well as combine operations between Rock Island and Grand Island).... so the total picture may not look that much different than what it is today, just would have put Fiat in a different bargaining position.
IHC is still alive and well in the truck and engine division. Actually, with the joint venture of CAT and IH, it's really too bad that CAT distanced itself from the Challenger line, there could have been IH power back in the field again.