I'm replacing the thermostat in my 4.9 (81 F150, 4spd, single carb) and have 3 temperature options: 160, 180 and 195(oe). It's hotter than normal this summer and sometimes have to sit in traffic for a long time. Any suggestions on which temperature to use?

Also, does anybody know if there is a steel water neck made for the 4.9?

Thanks

 

keep it stock. the water thats in the rad will be nice and cool by the time the stat opens up.

 

I run a 160 in my 85 4.9. When your engine gets to hot it starts to evaporate your fuel. So your gonna loose mpg runnin a higher temp thrermostat. It's not alot but it still saves you in the long run getting a lower temp thermostat.

 

the engines designed to run at 180-190 to get the best fuel burn. the fuel system delivers a richer air/fuel mixture when the engines cold..

 

http://www.extragasmileage.com/what-...rs-mpg-rating/

see, paragraph 5