XRAY - Model racing cars

Hello, yesterday i finished to mount and testing my new NT1 2013. At the end of the day i wanted to mount the harder springs on shock absorbers, but i see that the springs that i used in 2012 (only the short but always XRAY) do not enter the ring, it seems that slightly larger.
Does anyone know if you can adapt the old spring or if i must use only the new springs?

Thank you.

You can flip the shock spring collar (that adjusts the ride height) upside down.

Great!!!!!!!!!!!!!!!