ok, so a few weeks ago I put on a 3.5 pullley and FWI, now this weekend I am finally putting the 180* Thermostat in. Is there any other changes that I need to make to the car for the thermostat to run right, or is that it? Thanks, Brad

You are good to go.
Look to your exhaust for your next mod then pcm

there is nothing else to do but put the 180* in.. your fans will still come on at a higher temp based on the PCM peremeters, but the t-stat on its own will make a difference while driving.

As stated above, Next mods would be PEMs/headers, high-flow cat, and a PCM

Ok, i am getting ready to do this in a few hours when the car cools down some, quick question, what are the advantages of a drilled t-stat? Thanks, Brad

http://zzperformance.com/grand_prix/articles1.php?id=25