In your 2nd picture above, it looks like the alternator belt adjustment is out at the end of the slot.
There's no way to tighten the belt if it stretches in the future.
I would buy a shorter belt and put on while the hood is off, so the alt is mostly at the inner end of the slot.
They can be tightened with the hood on, if the belt is shorter.
Be sure to not turn the nut at the rear of the fan shaft, it can break the cast slot that holds the fan hub. Put a wrench on the 6 sided place on the fan shaft, just to the rear of the alt drive pulley, and turn there.
Hold the nut at the rear of the shaft from turning, if needed.
The new fan belts I buy at Case IH make the fan shaft a little less than half way up the slot, when the belt is tight.
They don't use the lower part of the slot, except to lower the hub down, to remove the fan belt.
I have seen on here it can make a problem with the position of the alt drive pulley being too low, if the fan belt is too short.
I sent you a message, you get to it at the upper right of the page.