With that offset and tire size you should generally be fine not to rub. You should not have to chop anything for a 32" depending on width, but all these trucks seem to be different, so it's really a game of chances. With a 32" though, I would imagine the most you might have to do would be get aligned at a competent shop and have them bump up your caster to be a bit more positive than factory spec, but throw em on and see where you're at.
FWIW I'm a 17x8.5 -10 with a 285/70 (33") and had to CMC and get UCA's that allow me to push my caster to 4 degrees, but now I should have clearance to fit a 285/75 (34") which will be my next tire size. Also not sure what tires you were looking at, but don't get Ridge Grapplers, they suck in every environment.