the 2-1/16" are the size i have in the cobalt. Fuel pressure, vac/boost, and wideband. Im not sure if they will fit in yours, they should either be 2-1/16", or 2-5/8". Here's a pic of mine.

 

That looks sick.

 

I ran 3 gauges in mine, fuel pressure, boost and exhaust gas temp... egt was usefull for towing in hilly areas as you could get off the gas when things got too hot...

If you're only gonna run 2 gauges I'd go with boost and fuel pressure for sure. Those were the 2 that Procharger recommended... if you are running an inline or a boost-a-pump knowing that if it fails you lose FP, may save your engine. I actually used my fuel pressure gauge to see that the stock Procharger inline pump was not capable of sustaining fuel pressure on 43lb injectors at WOT and was able to swap to a Walbro 255lph before I did any damage.

 

I was told the two imperative gauges were Boost and Air Fuel Ratio. AFR will give you a lean status if your not pushing enough fuel.

 

What wideband/AFR gauge are you using? I have the same setup with a PLX wb with a converter displaying to a Cobalt narrowband AFR gauge and would like something with an actual number readout.

 

I'm using the cobalt wideband.

 

I have the Autometer C2's. They are whiteface with the Blue light.

 

True... I guess if you plan on playing w/ the tune afr may be the more use full gauge.