seppe71, to clarify on the damper/rebound comment I made, you don't "need" them to run the Lyrik at 170, what you'll need is to know what are the correct oil volume values for the damper considering its year.
For one, the damper and rebound were revised in 2010 to allow more oil to flow between them, for that to be able to happen, on the rebound side of things, Sram took the tube, where the rebound used to sit inside the stanchion, out, completely, making a larger "head" for the rebound shaft that now runs directly on the stanchion. To be able to compensate that extra area that the tube no longer occupies there's the need of more oil than before.
For two, if you keep the damper and rebound you already have (which you can) you'll only have to make up for the space of 10mm more travel. I don't think I ever saw what are the oil volume values for it, so I can't give them, but I'm sure Sram or Go-Ride, if you're going to talk to them, will be able to help you on that.
Making the whole damper/rebound/spring switch, will probably be close to the $300 you mentioned, but according to all the latest reviews, on the Mission Control DH specially, it's worth it :thumbsup: