i own a 2008 liberty sport 4x4.

i need to replace 2 of the tires soon and was wondering what size can i put on with stock height. i'll be going with a a/t tire. not sure which one yet

I'm not sure on the max size for a KK without a lift, but you will need to replace all 4 tires if you have a 4x4.

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2004 Black Renegade, manual transmission, Frankenlifted, JBA 4.5 A-arms, 31" Super Swamper M16's on Pro Comp 8128 wheels, MagnaFlow exhaust, Volant cold air intake, and clear front signals.

He's right. You don't want to have two different size tires and two different brands if possible because they aren't always the same exact height. Differences in tire height will kill your 4wd drivetrain, unless of course never put in 4wd. Biggest tire you can fit stock is a 245/75/16.