69 camaro 305, new 3 row rad. long water pump. When I go for ride temp gauge climbs real fast 180-190 , then drops to 160. It will be fine for a while and will climb to 200 cruising. Does not always happen ,some days it is in normal heat ranges no problem.Thermostat maybe a year old, nothing has been done to car to cause a change.

Sounds like the thermostat may be sticking. I would try a new one and also get the kind that if it fails, it will fail in the open position.

This may have been covered elsewhere, but can anyone tell me if there is an advantage to running a 180 degree thermostat versus the 195 I currently am using? I realize the 180 opens 15 degrees sooner, but I've also been told that it may actually allow the coolant to run warmer, since it doesn't allow it to remain in the radiator longer, allowing it to cool more. My thinking is that once the thermostat is open it is open and has no control over flow. Am I missing something, and will a 180 thermostat help bring down the temperature showing on my temp gauge? Also would a 160 degree thermostat be even more beneficial?

Actually it does control the flow as the purpose of a thermostat is to maintain a certain temp. Not running a thermostat will cause the temp to go up because the water will not be in the eng. long enough to transfer heat from the eng to the water. Just from reading a lot of the posts on this site, it seems most of the guys use a 180 thermostat.

Thanks for all the help with my heating problem. Popped in a 180 thermostat, bumped up the timing and few other things suggested in the forum, and the cars' temp now stays under 1/2, closer to 1/3 on the console guage. It seems to go up to 1/2 cruising on the freeway, but is much better than it was. Thanks!!

The stat is there to warm the engine up quickly and then works with the other components of the cooling system. If you use a 195 stat you can expect to see 195 temps or just a bit higher then the stat opens and when the fluid is cooled down below 195 then the stat closes and the cycle begins all over. That said if the cooling system can't drop the temp below 195 the stat will never close and your engine will run at what ever temp above that the system flowing can balance. Same with a 180, but 180 is closer to what everyone feels is ideal... Ideally having a flowing system that cools down below the stat rating is what you want.