Use the ones that came off, unless, they are like really worn through.
If they look like they are just "molded" to the spring, then they should be okay.
If they have worn holes through the rubber, replace em with an OEM type isolator...like Casper said, the poly ones don't squish all that well.
For what its worth, I don't even run the isolators on my rears....the front, well, lets say mine is totally different.
May you fly low and fast
rest in peace JL