Hey all, I'm a new memeber to this forum although I have been reading the post for quite some time. I own a 97 grand prix GTP and am now in a position where I can begin giving this car the attention it deserves. (the old owner did virtually no maintenance in the 196,000 miles he owned it.) I've done a lot in terms of maintenance to it already but one thing I have yet to do is have the cooling system flushed. (Never been done in the 220,000 mile life) I want to do this in part cause it needs it and in part I wonder if I dont have a stuck open thermostat. The car runs about 210-215 in traffic and around 140-155 on the highways, I know these car usually run a little hotter but this seems off to me. Any opinions on the problem other than my guess, and also what temp thermostat should I replace it with. The car is bone stock. One other question I have is that I need to put a new coupler in the supercharger and while I'm doing this I was thinking of putting the 3.5" pulley on. Can I do this without having the PCM retuned or having issues with timing/KR.
