Fox

I would use what the owners manual calls for.

7upedition

I just installed a 180 in my 90 LX 5.0HO, it runs way better than the 195 i previously ren, also i have a 3 core radiator and hi milar hoses (mostly for looks) but the hoses dont get as hot as factory, also i am in the NE so its not as hot as the southern states, can runs at perfect temp. also the stock temp gauges can be off +/- 10 deg, good luck.

5.0_faithful

I use a good 195* thermostat, and my temps are always at 180*. I do have an edelbrock hi flow waterpump, hi-millar hoses, a new stock radiator, and a tranny cooler though.

7upedition

are you running a balanced high flow or fail safe thermostat, there really aren't that big of differences in t stat's as far as a good one or better one, they generaly work or don't work....just wondering what you meant, the waterpump prolly makes the biggest defference.

JeffUtica

Depending on geography and season you "normally" drive in 180^ is the minimum you should use for FI.
The purpose for the 195^ stat is "intended" to burn off as much of the fuel as possible, in the cumbustion cycle, to keep emissions low.
When the EEC see's temps below 180^ it forces a richer mixture. So the trade off is higher emissions and lower fuel mileage for improved performance. With lower temp you can run a littler more timing. A trade off I can certainly live with.
But with the good there is also the bad. Too rich of an A/F is not good as the extra fuel can wash out the rings and instead of having an oil barrier between the rings and cylinder walls, you have fuel. [] This can result in premature cylinder wear and worn bearings if A/F is not in check. For NA setups it's not really a concern because in closed loop the EEC is targeting 14.7:1 A/F ratio. At WOT it goes into a pre-set (by factory) open loop table and this is where it will run richer.
Those that drive in the south "could" get away with a 160^ providing that the motor does get up to the 180^ range. But if you have to run a 160^ stat to force it to stay cool I would start looking at the cooling system for prob's.
Temps in the south tend to allow the motor to heat soak at a higher temp as opposed to the NE.
Regardless of all this mumbo jumbo, IMO, a quality 2 row (1" wide tubes) aluminum radiator, high flow H20 pump, water wetter, aftermarket temp gauge that you can read actual temp, and electric fan(s) greater then 2500 cfm, will keep even the wildest beast tame.

5.0_faithful

I just meant that the stock 195* thermo is good . And your right the best way to keep temps down is with the waterpump.