Here's what I already know:
I have the right gears for my rear end (3.42)
the purple drive and white driven
I got a VSS new for a 90 camaro T-5

The only thing is the white gear I have has a shaft on it and the VSS has one too, so should I take the white gear off the shaft it came with and put it on the VSS shaft? Like this:............

 

Yup. As long as it fits and has the right number of teeth, you should be good to go. Should have about 19 or 20 for 3.42s.

 

Heres the deal, I have done speedo gear swap now for both 5 Speed and Automatic tranny's. The 5 speed turned out to be just like I thought, I simply took the gear off the shaft and stuck it on the little shaft sticking out of the vehicle speed sensor. I spnapped it on and has a little play in it but when you install it in the tranny, it seats against the tail shaft and holds everything in place. I had to jiggle the VSS just a little but it seated and fell into place like factory. All that was left was to plug in my weather pack connector and go. This was done to an 89 T-5 with a cable driven speedo. All I did was order the VSS and gears for a 90-up camaro with a T-5 and 3.42 rear. The VSS swaps directly into place where the calble driven thing was. I hope this helps out somone in my same situation

 

I am glad it worked out for you. I was afraid that it couldn't be done with ease after talking with you on IM.