The first and only 6L80 performance kit 

Glenn Troub introduces the all new 6L80-TOW&PRO Performance Valve Body Reprogramming Kit from TransGo. This kit delivers quick, clean, firm shifts with increased holding capacity, while maintaining factory shift feel at light to medium throttle with progressively firmer upshifts through WOT.
The #6L80TOW&PRO kit incorporates innovative boost circuit upgrades to bring a whole new shift feel to your vehicle. As always, TransGo makes their kits extremely easy-to-install with all drop-in components, including pressure regulator valve with line-to-lube, TCC regulator valve and spring, solenoid regulator, clutch select valves, O-ringed end plugs as well as a cooler bypass delete kit for 2014 and later vehicles.
If your high performance or street show-off vehicle has the horsepower, this kit includes simple to follow instructions for HPtuners or EFI Live that will produce 1-2 and 2-3 tire-chirping shifts that will surely bring a smile to your face.