996 springs/struts on a 986

[j.fro]

For the rear, Boxster and 911 suspensions are completely different and the struts will not swap.
For the rear, the strut bodies are the same, but the spring rates are not. If your Boxster struts are toast and the 911's are good, you should be able to swap the Boxster coils onto the 911 struts.