Springs are the same size for M or non-M. WUTANGM3, when you say these will fit M3, were you able to get the specific part number? Or are you just generalizing, since all e36 springs are the same size?
If they are M3, the higher spring rate may destroy non-M shocks. Sport shocks 'might' be okay, but hard to tell. All guess-work without more details.
2002 540i M Technic
1993 325is RIP