I have a 1990 Ford F-150 four by four 5.0 it called for 265 75 15 but someone put 31x10 15 and it don't seem to shift at the right shift points can it be calibrated for them tires

 

I didn't think Ford ever put a tire that big on that generation of truck, even on a 4x4. Most trucks in 1990 still had 235/75R15's. That's a 28.9" diameter. A 265/75R15 is a 30.6" diameter. If you meant to write 235/75, then yes, a 31" tire is a big jump. If you meant to write 265/75, then a 31" tire is just barely taller, probably not enough to even see. I may be wrong here, and someone please correct me if I am, but I don't think a 1990 truck's transmission communicates to anything. It's purely mechanically controlled. If you went from a 28.9" tire to a 31" tire, you basically raised your rear end gearing by over 7%. So if your truck has 3.55 gears stock, those taller tires just turned them into 3.31's. You're putting less torque to the ground. It's probably going to feel sluggish because it just can't pull/accelerate like it did stock. Your speedometer is off by that same percentage. So if you're showing 70mph on the speedo, you're really going around 75mph. You can correct the speedo by changing the speedo gear at the trans. But if you want to have your original power/torque back, you'll have to re-gear (both ends, of course). The math says you'd need a 3.81, which I don't think exists, so the closest is a 3.73. Hope any of this helps. Again, though, if you meant to write 265/75, then your engine/trans should never know the difference. Good luck!