u/Fluid-Victory3802

I have two 1000w subs. And I also have a box but for 400w subs. Can I damage my new 1000w subs if I put them in my old box? Also a question. The subs I’m using are ground zero gziw 12xspl- d2. Some websites lists rms as 1000w while some list max watt as 1000w. Can I give them 1000w continuous whiteout damaging them?