I know theres alot of threads on this but I want to get an answer for my truck. I'm about to replace the plenum plate and gaskets, and while I got it ripped apart, I'm going to put a new thermostat in. It runs around 195-205 here in Oklahoma where it's in the 100's everyday. I want to run it cooler, thinking about 160. What would be better to go with 160 or 180?

 

Everyone recommends 180 degree here. Stock is usually 195. just did 180 on mine runs way cooler on the gauge. Ive read here on the form 160 is too low and can cause check engine light to come on for some code. Get the 180 and if your still worried do a coolant flush and/or add an electric fan.

 

Yeah that's what I've been reading to, but is there really any performance gain when it runs cooler? And how does it affect fuel mileage?

 

To be honest, I believe in what I've read as far as the 160 being to low. Also, if you look at the gauge on the dashboard notice there is an extreme heat reading then a drop off too low reading? I would assume that being at a temperature below the low side on the gauge is not how the vehicles engine was designed to run. 180 puts the gauge slightly under the middle which we could assume "normal" running conditions (200). when I run 180 my engine runs 190. with the 195 I run 210. If your looking for performance goto rm-indy.com and see what he puts in as he is a performance gear head. If you go crazy reading the forum youll see some have issues with 160 none have issues with 180 some 195. All i can say.

HeyYou??? whats ur 2 cents

 

So 180 would probably be the better choice then?

 

Ive done alot of reading about it as I am doing my kegger mod, plenum plate, water pump, timing gasket, e-fan. and have personally dropped the 195 and put in 180 and had a great experience since. Everything ive read on Dodge forum for our gen truck 180 would be your best bet and your already getting better performance. There is always an extreme to each side. Liquid Nitrogen vs Magma :P

 

Just googled operating temp of a mopar small block magnum engine:

Result:

normal operating temperature 180-200

 

Ok so 180 it is, thanks man

 

I should get some performance gain after the new plenum plate install right?

 

If your plenum gasket is toast, and you replace it with the hughes plenum plate kit and clean out your intake you will have a couple effects. 1) Sealed intake with no leak therefore you pull all air from your air filter. 2) Clean surfaces tend to promote better air flow. 3) You prevent your cats from getting clogged and your O2 sensors from going to crap $$$$$$ 4) You may never have to take the intake manifold off again unless bigger problems arise in your motor. 5) your engine will be running cooler with the new thermostat your installing.

While doing the plenum seal may I recommend you get
1)plenum plate, gasket, new intake bolts
2)thermostat housing (like 10$)
3)thermostat gasket + 180 thermostat
4)thermostat sealant
5)throttle body cleaner and gasket
6) if you really wanna go nuts you can replace sensors. there is a couple depending on year

Check out the plenum thread, and also the Kegger Mod DYI. then you can get a real idea of all the stuff that you can replace on the intake manifold since your doing, and some would rather spend some money then have to do it again. I am in that boat.

Cheers and good luck man
Post us some pics of what you did it will help all of us!