5 pages for this?  I think it was answered thoroughly in the first page ;-)  The rest is just filler, so I might as well weigh in too.
A standard 1/2" DeWalt electric impact is rated for 345 ft/lbs.  My air impact is rated for 425 ft/lbs (I think).  The proper torque is important, so I recommend that you do it the same way 99.9% of people and mechanics do it when they install lug nuts: tighten the goober mess out of it with an impact!  I've never seen anyone check torque on lug nuts, yet that's just as important as the issue at hand.  And remember, that 260 ft/lb torque spec is required for max load and engineers almost always include a safety factor of "2", so just tighten it with an impact and move on.