Didn't someone like Shinycar have his Koni shock mounts rejigged by his Koni distributer in Oz? That's probably the thread you've already read. I'm sure you could an engineering company to do the same as Shinycar.
So is it actually the damper that's too long and holding the weight of car up instead of the springs? If not could you put twin spark springs in the front so the engine weight compresses the springs more?
I suspect it's the Eibach springs that influence the front rideheight more than the KONI dampers. But I don't recall reading about rideheight
on V6 GTs using KONI Sport with different springs, or Eibach Pro Kit with different dampers. So I'm not 100% sure about this.
Eibach + Bilstein possibly ends up lower; don't know.
Anyway, yes, you could follow the lead of what KONI Australia did to my suspension. Any good machining workshop should be able to do the work:
1. shave off some of the top of the suspension fork: I don't know exactly how much they removed, but you can use my pic for reference; I suspect about 8~10mm
2. cut off the top of the 'hook'/bolt hole on the damper
In effect, the damper 'sinks' down into the fork, resulting in lower rideheight.
I can only think the reason Eibach (or KONI) have done things the way they have, is to prevent the car from bottoming-out. When the V6 GT or GTAs are lowered, you'll be scraping the undertray when the suspension is compressed heavliy (eg: at speed over a dip/bump). Fitting an aluminium undertray improves clearance. However, I also have aftermarket stainless front pipes fitted, and these have scraped the road (a higher undertray is not going to stop this happening).
Did you adjust the height after changing the suspension? cant really explain but i did a diagram for a friend when i changed my shocks, check photo.
What do you mean by this question? The height is not adjustable, except by changing springs (or maybe dampers), or fitting coilovers with adjustable spring perches.