If you're going with a 520 chain you will need new front and rear sprockets (unless those have already been changed).

 

right now i have -1/+2 or maybe +3, they guy i bought it off of said he couldnt remember
but my chain is stretched to max, so im getting a new chain and sprockets.
i found a good vortex -1/+2 kit, and im not that worried about being lightweight or anything
so what chains can i use?
is the 520, 525 like the width or something?
will either work with the set up im wanting?