Most of the brand will void warranty once the default cooler is changed, I never heard of after sales warranty cover those mods, OC as well.

If you want to claim warranty later on, pandai pandai lah.
Change back original heatsink, then never say a word about you've change to other heatsink or open any parts of the screw lor.

Becareful of the sticker that stated "Warranty void if sticker rosak/opened, etc"