According to the Ford Service Manual it's 40-65 ft-lbs. Note that my 98 manual describes this part as an oil cooler, while late 98 models (including mine) did not have a cooler, but just an adapter. So taking a look at the 99 manual may be a good idea.I have not been able to find the torque spec in ether my Haynes or Chilton manuals.
Seems that the CD was updated, so I would trust it more than the printed book. Looks like they also got rid of the confusing range and provided just a single number, like was done for later models Thanks, donalds.I just selected his vehicle in the ford CD
Then went to engine assembly
Scrolling down to the info he needs
It is the 90 degree filter adapter.Do you have the 90 degree filter adapter, or, the oil cooler? I strongly suggest deleting the cooler version in favor of the straight thru 90 degree bypass-adapter.
The cooler will give problems down the road at some point, and, the hose replacement on them is a PITA