996 springs/struts on a 986
 

Is it do-able, and is there any merit?

I have a set of free coilovers from a stock 996TT

Not too sure about 996TT but I just redid all the suspension on my car.
Front strut mount has same part number with 996/997. All front suspension components has either 996 or 997 part numbers. The rears on the other hand, have 986/987 parts except the control arms which are the same as the front (996 parts).
I think the front might fit but the rear would be completely different from 996.

I just purchased rear struts from a Porsche 996 to replace my rear struts on my Porsche 986. I was told that they are compatible and will work. I just want an expert to tell me before I remove them from my 2001 Porsche Boxster. I would appreciate some assistance please. The rear struts came off a 2000 Carrera. Thanks for your time.

No how/ no way. The rear suspensions are quite different between a 986 and a 996. The C4S/ Turbo cars are different than the "base" C2/C4 cars, both in the front (AWD), and rear.

Even if you could get them to fit, the spring and damping rates will be way off.

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.

Thanks so much for your comments. I think that it will be best if I just sell the rear struts and purchase the correct ones for a Porsche Boxster. I should of asked before I purchased them. Lesson learned! Thanks again for your help!

From handling these, but not comparing them to each other, I think you are correct here on a "base" C2 or C4, but the Turbo and C4S use a different upright, so I think all of that is different there.

Either way, the damping values are all different, so even if they did fit, and you swapped springs to the correct rate, it's still not going to be a good setup.

Likewise, you could use 996 C2 front bits, but not C4, C4S, or Turbo bits.

The whole thing is a bad idea.