with 180 thermostat should......
 

my temp gauge still read just a hair under 200? I just installed a new thermostat and wife drove the car about 35 miles round trip and I just checked out the car and the temp was at 200 :? Is this right? Is that 15 degrees to small to notice on the gauge?

After I installed mine, I noticed that the temperature gauge read just a smidgeon less than it did for the 195. Much will depend on outside temperatures, the type of driving, as well as the sensitivity of your gauge. Some will read slightly lower, some won't. They're an approximation, and like to hang out around the middle of the gauge.

The 180 tstat will reduce the running temp slightly, but the main thing it does is slow the heat progression towards that limit. Especially if you drill it.

without reprogramming your PCM, the fans will still come on at the same temp, therefore unless your at cruising speeds, the coolant will still heat up until the stock fan temp is reached. the 180* t-stat is only one step, a PCM reprogram completes the temp reduction

what is involved in a PCM reprogram? What is the first step in doing so?

you need to get a PCM from INTENSE

or DHP or ZZP

I have a 180 t-stat in both my '98, and my '00. In the '98, after the new t-stat, it ran noticeably cooler on the gauge (except when idling with the a/c off, etc). You could see that the opening point had lowered. In the '00, the gauge reads the same after the 180 t-stat as it did before. The gauge in the '00 points to just below 200 degrees after it warms up, and doesn't fluctuate nearly as much as the one in my '98 does.