Anyone know the ID of the ratiator hose?
 

Im putting a water temp sensor in to control my electric fan and i cant exactly get in there measure the ID. From what ive rear i believe it is 1.25in. Is that correct? Also would you put the temp sensor before or after the radiator?

I found 1.5" tubing fits inside pretty tight, so it probably is somewhere between 1.25" and 1.5". For fan control I like it after the rad or near the bottom. That way the fan shuts off if you have lots of natural air flow like at highway speeds.

1.25 according to Gates.