My Tracker's got the 6" Calmini lift system and I'm driving it around on 215/75R15 Goodyear GSA's on stock wheels right now. Looks like a big rollerskate.
Gas mileage went up though.
I can tell it's a little more "wobbly" around corners than it was with 31x10.5R15 tires on 2.5" backspaced wheels...but not a whole lot. I was expecting to crap my pants at the first corner...I told my wife she probably couldn't drive it like this (coughleadfootcough
) but you know, it handles just fine. The tires are completely under the fenders, just like stockers, and the 31's stuck out at least 4" from the fenders...and it drives fine.
Don't buy the hype that lifting a vehicle necessarily turns it into a pogo stick or whatever. I think the better truck tires you got with their stiffer sidewalls will more than offset the little bit higher your CG would be with 1.5" of lift. My prediction is you won't even notice a difference.