on tire rack
they say either of those sizes could be OEM tires for your year...
bet it has something to do with GVWR and GAWR for towing...
were the 265's already on your truck and original tires?
maybe the previous swap got the wrong ones then
See what 'should' be on your truck based on your equipment...
and go to tire rack for the recommended tires
The new tires
Compare load rating, size (height, width, revs per mile, etc...)
to see if they are comparable....
This is one of the things that you should have in hand before you go
and maybe they sold you what they had !
and FYI, spent 3 months in your area - beautiful area but I put on 10 lbs eating at that place right on the river - The Depot Grill - always wondered if it got damaged/closed from that train derailment - think it happened right in front of it ????