My T56 is out of a 2006 Viper. A "Viper Spec" is a non Viper T56 built up to Viper Specifications. A Viper T56 has a longer input shaft than a Cobra T56, so you will need some custom work done to bolt the Viper T56 up using a Cobra bell. A Viper T56 will have a Viper emblem cast into the shifter boss on the case.
Forgot to mention, the Viper T56 VSS is 3 prong. Ground, 5v, and speed signal. Do some research and you can find some work-around for this. I don't have ABS so I used an ABS sensor from the IRS to send a signal to a programmable Autometer electric speedo.