1995 OBD2 VSSB/speedo calibration?
 

So, I've been doing some research on how to correct my speedo after I had the 33" tires put on. I've read about how to correct it on 90-95 trucks, by modifying the VSSB. I'm planning to install dip switches if this is an option.

My question, is does my truck have a VSSB, or is it all ECU controlled? It's a 95 model year, but it's fully OBD2. The computer is under the hood, passenger inner fender on top of the coolant overflow tank. I also have an OBD2 port, and my OBD2 scanner communicates with the truck.

Can anyone clear this up for me? Also, if I do in fact have a VSSB, where exactly is it located?