My 68 with a 350 has a temp reading on the gauge around 205 degrees. I have no idea what the thermostat temp is. This is 90-100 degree weather with high humidity in Austin texas. While sitting at a light it will creep up to about 220 degrees and slowly go down once moving down the road again. It is not over heating and coolant level is fine.

The engine does have a mild cam in it along long tubes (no coating) and a trans cooler sitting in front of the rad. The tranny is a 700R4.

I am just curious what people think the thermostat is? I don't want to go buy another 160 if that is what it already may be.

Thanks
Ray

Depending on where the car came from when you bought it,southern states with tipically warm weather its a 160. If the car came from colder weather state it may be a 180,190. small blocks are typically a cold starting motor.I live in central fl and dont use a thermostat. your cooling problem is probably something other than the thermostat.
greg

If your car is gonna run 200 plus degrees it is gonna do it with a 160 or a 180 degree thermostat.

depends on where your temperature probe is mounted. i had mine in the side of the cylinder head. had a 180* thermostat but the gauge read a constant 200*. the fact that the gauge was constant under normal conditions tells me the thermostat was doing its job.

if you're reading a constant 205* going down the road, i bet you've got a thermostat higher than 160, 195 maybe.

why do you think you need a 160? like greg and robert said, if your temp creeps up like that it's gonna do it no matter what thermostat is installed.

If you have already done these two things, then I'm out of ideas. First, have you checked the timing? If the timing is off, then the car can run a little hot. Second, is your fan working properly? Does it have a radiator shroud? If you have a clutch fan, then try turning the fan by hand (with the engine off of course). You shouldn't be able to move it.

Does the car smell like its running hot? After you have changed the t-stat to a known temp, check your reading again. If it is still high, it could be the gauge itself. What type of gauge do you have in your car? I had this problem with a sunpro electric gauge in my 'Cuda. It worked fine for 10 months, then decided it wanted to stay on 210 while I was driving. I swapped the gauge out for an autometer phantom gauge and have been on a constant 165* since then. Its worth the $ to have good gauges. I won't buy any but autometer from now on.:thumbsup:

seems to me you need more airflow at low speeds- if you don't have them, the proper fan shroud and a good fan will help a lot.
but really, 205-220 isn't anything to worry about as long as the car runs good and doesn't boil over.
my Monte has a 195 thermostat in it and runs about 200 degrees when going down the road. the 94 Caprice LT1 electric fans kick on at 215 and shut off at 205. it takes a little bit to get used to the temp gauge reading that high, but when you consider that some cars are set up so the fans don't even kick on until 225 degrees, 220 doesn't seem so bad.

I do not have a cooling issue, I am just trying to figure out what the t-stat degree may be. The car runs great, has a fan shroud and clutch fan that works fine.

I have autometer guages that are mechanical and the probe is in the intake at the front of the engine near the t-stat housing.

Thanks for the thoughts guys. I am just thinking that I may want to be a 160 in just to get it a bit cooler during the 95-100+ heat and 90%+ humidity here in Austin TX.

Ray

You say you don't have a cooling issue, but the temp shouldn't get that high while sitting. My car can sit in 100*+ weather all day and never get above 200*(electric fan turn on temp). There is something making it get that hot and I seriously doubt it's the stat because the temp drops as soon as you start moving. That usually indicates an air movement issue. Perhaps the radiator is dirty. What type of fan/shroud do you run? Perhaps it has the wrong shroud installed? Is everything original, engine wise? I know it has a 700-R4 tranny. What about A/C? What is your timing set at? We need to know more about the car to give you a more informed answer. What

No A/C stock fan shroud with a 3 core rad. edlebrock intake, timing set at 8 degrees. Idles at 800rpms at a light. Even my stock 01 and 06 corvettes have the temp go up at a light and then go back down once start moving.
I am running about 75% water and 25% rad fluid.

I do not have a cooling issue, I am just trying to figure out what the t-stat degree may be.
Ray

The only way to figure out what temp thermostat it is is to take it out and read the numbers stamped on it.

And I agree that you don't have a cooling issue.

if it's gonna run at 205 with a 195 t-stat, it's gonna run at 205 with a 160 t-stat.
it will just take a bit longer to warm up 5to that temp with the cooler t-stat.
the only thing the t-stat does is set a minimum operating temp by shutting off water flow out of the block until it reaches a certain temp .
if you really must get the temps down under 200 degrees for some reason, then get external oil and trans fluid coolers to get that heat out of the coolant.