The inserts actually don't require welding (I believe the bilsteins do, but not the Konis), but they do require cutting your existing perches. The inserts are the same Koni Sport inserts you would install in the Sachs perches, however, you get to maintain the threaded perches of the M030 for true coilover adjustability.
Available from Paragon (I prefer to go to them for their longtime support of the 944 community), and currently on sale for about $430 plus shipping for the pair. The
matching Koni Sport rears are also on sale for $350 right now.
The other option rather than cutting up your rare M030 coilovers is to have them rebuilt. Last quote I got from the authorized service center,
Performance Shock, was $350 per shock, base cost. More if revalving or additional options.
You could pick up a pair of cheap blown Sachs shocks to chop up for the inserts, rather than chop up the M030s, but any of the above are good options.
EDIT: as
@johnb notes, there are some modern options too, but everything I could find resulted in a lower car, and I'm just squeaking into my current garage without scraping so none of those were options for me right now. The options I bookmarked for the future were:
- Riaction, which seem like very good value at $1300 (base... there are several options) and still a bump in performance.
- KW V3s seem universally loved but run $4k.
For either of those, you'll also have to either re-index or remove your torsion bars, given the rear coilovers.
FWIW, Jason at Paragon feels like fresh Koni Sports are still pretty good options for street use.
