If you have 18" drawer slides but want to make the drawer 20" does it matter that the slides don't cover the last two inches?
Thanks
no, it doesn't matter, they just won't pull out all the way.
Only if you only want the drawer to slide out 18", not 20", They will be fine depending on what you are putting in the back of the drawer.
you can get 2" over travel slides as well so you could still get to the back if you wanted