Alright I'm sure someone knows my answer to my question, what's the diffrence between motorcarft thermostats and ones at advance auto parts? I currently have a stant 195 degree theremostat in it.

 

Motorcraft are better quality... it is also designed different in how it directs the flow, whereas the aftermarket ones do not.

Motorcraft # RT139

Josh

 

I would go with a robert shaw thermostat. They are built to close off the internal bypass when the thermostat opens on the 351M/400 engines. The advance auto, etc will fit but they are not the correct application. I have also ordered motorcraft thermostats from a ford dealer that were the wrong application. The robert shaw number is 333-192, or 333-180, depending on what temperature you want. They are available from flowkooler.com and are $12 - $15.

 

Thanks ill haft to get one