Fox Commercial Series- 980-31-008 Fox shock - Peterbilt/Kenworth rear shock. 
980-31-008 Fox shocks are heavy duty military grade drop-in replacements made in the USA. They are backed with a 2 year/200,000 mile factory warranty.
Part Number: (old) 901-100-001 (new) 980-31-008
OEM Reference Numbers:  C71-6015, C71-1016, C71-1002, C71-6000
Monroe Reference Numbers:  65495
Gabriel Reference Numbers:  85067, 89451
Kenworth, ICON 900 w/ AG380 Rear, 2016-2017
Kenworth, T440 w/ AG380 Rear, 2012-2017
Kenworth, T470 w/ AG380 Rear, 2010-2017
Kenworth, T660 w/ AG380 Rear, 2008-2017
Kenworth, T680 w/ AG380 Rear, 2013-2019
Kenworth, T700 w/ AG380 Rear, 2011-2016
Kenworth, T800 w/ AG380 Rear, 2001-2018
Kenworth, T880 w/ AG380 Rear, 2014-2019
Kenworth, W900 w/ AG380 Rear, 2001-2018
Peterbilt, 367 FlexAir (38000 lbs) Rear, 2008-2019
Peterbilt, 382 FlexAir (38000 lbs) Rear, 2011-2017
Peterbilt, 384 FlexAir (38000 lbs) Rear, 2008-2016
Peterbilt, 386 FlexAir (38000 lbs) Rear, 2006-2016
Peterbilt, 388 FlexAir (38000 lbs) Rear, 2008-2017
Peterbilt, 389 FlexAir (38000 lbs) Rear, 2008-2019
Peterbilt, 567 FlexAir (38000 lbs) Rear, 2014-2019
Peterbilt, 579 FlexAir (38000 lbs) Rear, 2013-2019
Peterbilt, 587 FlexAir (38000 lbs) Rear, 2011-2018
Some of the benefits include:
Heavy duty military grade
Drop-in replacement 
Made in the USA 
Backed with a 2 year/200,000 mile factory warranty 
Dyno tested at 35% more rebound and compression when compared to stock OEM shocks
Better roll stability for safety/ride comfort 
Longer tire life
Less airbag failures
Rebuildable/serviceable