Jonblarc has a K2xx truck. I dunno if they used a 14 bolt with the L86 trucks, but at the very least he has on of the new 12 bolt axles

 

Randysworldwide.com shows it going from 4.11's to 4.56's on my truck

 

I went from 4.11 to 4.88 for towing. Pulled a 26' trailer at 7,000lbs on cruise control. it was nice and easy. Upgraded to 38' 5th wheel at 10,000lbs. It pulls with a little more difficulty, dropping down to 2nd gear at 45 mph for short periods.

 

ah, gotcha... wasn't aware of the new 12bolt diffs.
my bad