Worst case, you will get a "speech" from your tire shop, but ultimately, if they want your business they will install the tires that you ask/pay for.
I had 265-70-R17's on my 2003 Limited and they worked fine, they did not rub, even at lock, and the truck seemed about an 1" taller. Speedo was out by about 4% slow (you were going actually faster then the speedo says)
I actually just switched back to the stock size... (and got another "speech" from the tire shop).. I actually like the truck better with stock size.
I've actually had a longer speech from tire guys when I asked to install non-speed rated tires on a car that called for W or Z rated tires.
Long and the short of it... I demanded the non-speed rated tires and they installed them.