http://www.hawksthirdgenparts.com/in...ROD&ProdID=910
I know I will probably need it since now I have 28'' tires and the 3.73 gears that are going in. But how does it work and where does it go? lol

 

I've got mine part way installed (I burned a wire on the exhaust and don't have the patience (sp?) to fix it right now). There is more info at http://www.dakotadigital.com/index.c...rod/prd126.htm . As far as I understand it, it takes the signal from your transmission and changes it so the speedo reads the correct speed. It has a couple of different options (hence the many plugs) and can be recalibrated as many times as you like, so whenever you change to different tires. All you have to basically do is splice into you speedo wires somewhere along the line and install the unit somewhere in your car (I'm putting mine in the ash tray because I don't use it anyways). One thing to note though, the instuctions may look overwhelming at first, but once you find which option you are going with it it pretty much a piece of cake.