Hi Mike.
I have been researching the same sort of stuff for awhile now, and finally down to the short strokes before I order a set for spring.
Here are some bits I found useful which may also help you.
What a 225/35/19 might look like on an 8.5" rim:
http://tyrestretch.com/8.5_225_35_R19/
(225 is the minimum size for an 8.5" rim, 235-245 is preferred, 255 max)
http://www.kouki.co.uk/utilities/vis...ize-calculator
What a 235/35/19 might look like on an 8.5" rim:
http://tyrestretch.com/8.5_235_35_R19/
They don't have any similar 255 or 265, but poke around.
Two other interesting offset/sizing tools:
Rims n Tires:
http://www.rimsntires.com/specs.jsp
Will They Fit:
http://www.willtheyfit.com/
Just watch your ratios front-to-back: 3% max for RWD, 1% max for AWD.
Good luck.
