Hi Mate,
I fitted kings and Koni yellow adjustables to my near new SS-Z two weeks ago so i think i am the man you want to hear from. Firstly the ride height, will get to the damper later. If you want the car to sit with a fairly even gap over the front and rear guard then you need a higher spring in the back as the way they set mine up initially was super lows all round (HD's in the front) and i found that the yes whilst the sill was horozontally level with the ground the back end looked like it was way too low with the guard over the wheels. So I had them fit the Low HD in the rear and now the front to back proportions are to my liking re the ride height. Dont let any suspension shop tell you the v8 HD king spring will be too firm, that is garbage, i found the suspension shop to be pretty conservative re this. Anyway the Koni's. Note that the rears cannot be adjusted while in the car, only the fronts can so rear shock adjustment is critical. Initially mine was set up with a quarter of a turn up from softest in the rear and softest in the front. This provided a very comfortable ride (like OEM comfort) but the whole thing felt more ties down and that floatiness was gone. It was also more responsive. I wasn't happy as it wansnt sporty enough for me. I played with the fronts and found that putting a full turn on the front adjustment took most of the body roll out of the front, turn in was very crisp, lighter, and whilst definitely alot firmer than the softest setting, it was not in any way uncomfortable or harsh. Rough stuff was still relatively smooth therefore showing how good a high quality damper like the koni's are, not only is the ride very sporty and direct, it also retains a level of quality and smoothness you just wont get in cheap tein coilovers or monroe GT Gas etc. Anyway, when i had the rear springs changed to the taller HD's, I had them tweak the rear shocks to one full turn from softest and i run 1.25 turns on the front. Its not harsh at all, it just handles fantastically for a street car and I reckon this setting will go allright at the track too. I also have a front castor kit in so they could get the alighment right. The Bilstein is a great product but will be firmer that described above and does not have any adjustment. I'm really glad I went the Koni's, they are brilliant and i'm happy with the front SSLHD and rear SLHD spring combo. bloody big reply, sorry mate, take what you will from my experiences with it.