I've got a 300hp crate 360 magnum in my 91 power ram 150 4x4 short bed truck, I'm running a Napa premium 195 thermostat, a 3 row brass/copper radiator, 5 blade mopar viscous fan. I never have any over heating issues, the hottest this engine has ever got was 230 while I was working it real hard climbing in 4wd.
I'm running an aluminum dual plane mopar m1 intake and a quick fuel super street series 680cfm vacuum secondary carb. I've been told I would have a little more power if I switched to a 180 degree t-stat because the intake will be a little cooler.
It's only about a 30 minute job to swap t-stats, and I can get a 180 t-stat and gasket for about 10 bucks, would it be worth trying? I'm not to concerned about fuel mileage, but my heater is pretty important in the winter months. But I've never ran anything but a 195 t-stat and if there is a little more power to be had by going with a 180 then 10 bucks and 30 minutes worth of labor seems worth it to me.

"just me" I would dial in the dist and carb to gain some power. Here's a BTT for ya

Distributer is dialed in, im running 16 degrees of initial timing and 34 degrees total timing, all in by 3000 rpm. Carb is dialed in the best I can get it by ear and by vacuum gauge and by looking at the plugs. No hiccups or stumbles anywhere, although I think it's a tad rich at full throttle. I'm going to get a wide band soon.

If you've got the engine dialed in as you're suggesting I'd think there'd be more to be gained by grabbing some cooler,denser air for the incoming mixture instead of trying to cool the engine/intake by changing the thermostat...But experimenting is the fun part and all small gains may add up in the end...

Excellent idea

How do I get cooler, denser air? I'm running a 14x3 wix racing air filter right now.
I was under the impression that by dropping the t-stat down from 195 to 180 would cool the intake off more, therefore making the mixture easier to burn... Is that wrong? I re-searched running the 180 t-stat a little and everyone says a cooler running engine makes more power, a hotter running engine will run a little more efficient. So you lose a little efficiency by going to a 180 but you gain a little more power. Is that wrong?

you would run a closed air filter housing with either single or dual snorkels & route fresh air to them from the front of the car like the rad support area with similar to dryer ducting so the eng is ingesting fresh (colder) air as opposed to air that has been heated up in the eng compartment

Efficiency is not just defined by more MPG.

A more efficient engine can also make more HP per gallon.

Gasoline needs to be in vapor form to burn and heat helps it vaporize.

I doubt you'll notice any gain in HP jut by changing the thermostat as others have said, it's in the tune.

Modern engines make a lot more hp per cube than older ones and the run a lot hotter doing it.

The reason cooler air into the carb makes more power is that cooler air is more dense so you get more oxygen per cubic foot. Again, you'll note that modern vehicles all use some sort of cold air setup. Back in the day when the carb got it's air from underhood it made a difference to lower the engine's running temps because the hotter the engine ran the hotter the air under the hood. Today, that's very old school thinking.

I'm surprised, all of the advice you've been given is correct.

Your idea that a cooler intake charge is easier to burn is backwards..A warmer mixture probably has the fuel more totally vaporized and thus easier to burn. As said above, the real power increase is that cooler air is denser air, so you can get more oxygen and fuel molecules into the engine, thus making more power.

The open element air filter sitting under the hood isn't the way to more power. Ducting cooler outside air into the filter is.

Unless you are a class racer who is looking for the next hundredth of a second, switching thermostats won't do anything.

The most power for a combination is obtained when the coolest possible air is inducted along with the fuel in optimally sized droplets. When the fuel is completely vaporized before it gets into the engine, it actually reduces power because the gaseous fuel takes up room that could otherwise be occupied by oxygen molecules. Thus the droplets make more power even though they are not as easy to burn as completely vaporized fuel.

R.

Don't forget the latent heat of vaporization adding in a cooling effect. Essentially as gasoline, or any fluid really, changes state to a gaseous one it draws heat out of the ambient surroundings to use as the energy to change states.

Part of the reason why water injection does what it does so well.

Ever get acetone or alcohol on your hand and notice it gets real cold evaporating? Same thing.

One difference with a carb and cold air induction vice EFI and cold air induction. On an EFI system it uses a high pressure fine spray pattern out of the injectors to help vaporize the gasoline, carbs use heat.

If the inlet air is too cold carbs have to really be richened up to get enough vapor to run an engine. Like a choke in cold weather. This really kills efficiency from both a MPG and HP stand point.

You will see more bore wear with a cooler t-stat, less heat, less MPG and barely any more HP, the gain from denser air is somewhat offset by thicker oil among other things and the gain ends up very tiny. I live in montana and love me a 205* t-stat !

I'm convinced the 195 t-stat is just fine, I live in Idaho, I like my heater in the winter.
I notice your from kalispell hotroddave, I used to live in Missoula, kalispell is a beautiful town. I live in Idaho now. I'm only 140 miles from Missoula though.