let me check on the range, may have thought of the wrong ac....sorry, wrong ac...(unless you have a weaponized 788)
Here is the explanation of the B from the Pilots Guide on the 4000, 6000 should be the same...
is this what you are looking at?
Here is a link to the Pilots guide...
https://www.scribd.com/document/84774262/B737-HUD