Any machinist worthy of the name can adapt tapered roller bearings to hubs intended for ball bearings. Other than a cost and availability advantage in favor of the tapered bearings, I can't see much of a reason to go to the effort and expense to do so. Since very few of our trucks see working conditions approaching what they were designed and built for, "upgrading" to a higher capacity bearing is a fool's mission.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!