If you are just looking for a tap up / tap down switch for the 8L90, see here.
Tap Shift is enabled when you shift into manual mode (M), which is one gear below drive (D). To exit manual mode, simply shift back up into drive and the transmission will resort back to regular automatic shifting conditions.
Disclaimer: You must be running the E92 ECM with a Corvette OS to gain full functionality of the Tap Shift. Tap Shift will still function in DRIVE mode with non Corvette based tunes, but will time out after approximately 8 seconds of inactivity, and resume back to automatic gear changes.
Will not work with GMPP computers!
Comes with an instruction sheet for easy installation.