I must be doing something wrong. The max I can get out of GAP is 29mm - which is not close to 1.5” let alone 3”. Are you saying those adjustments are achievable with GAP?

 

I just want to add some info for people:

While I have tried to educate people for 15 years now about all the negatives: "shorter rods are not-really-a-lift", they are however, required, if you do install air strut height spacers. This is purely because when doing so, the 50mm spacers extend the struts enough, when in factory off road height, that the computers freak out over the sensors beyond beyond or right at their range. The rods allow you to calibrate the system back to having the struts at their normal/neutral length, which puts the sensors back into the middle of their happy zone.
The result is the vehicle sitting at roughly 50mm higher off the ground but with the air struts still at exactly the factory normal ride length.
Early on, 2008, I did a lot of testing with my own DIY shortened rods by taking a factory set, cutting them, then tap and threading the shafts to create an adjustable version. What I found though, for the most part, was that I could also just place a large wood block under the slider, right up to it when in raised height, then lower onto it, causing the system to go into "extended mode", which was basically the same height as using short rods and flipping the offroad height lever. So in reality, no benefit to having the rods but with all the negatives of just driving around all the time on extended struts.

The real improvement with these is to make the necessary mods to allow larger tires in conjunction with the strut spacers (bump stop lowering) such that an LR3/4/RR and now L663, could run on much larger tires without worrying about grinding out the fender liner when fully articulated or if the rare occasion of air system failure.

The modern way to "lift" and L663 by way of the sub-frame spacing is game changing but a hell of a lot more work and cost. I did the strut spacers from Lucky8 about 10 years ago myself in the driveway during a full overhaul of all the suspension and brake components. The LR3 uses 34" tires on factory 18x8 with no wheel spacers and has 100% free and clear articulation.

I wonder what is the best method for the L663 but am guessing its the sub-frame spacing plus fender area trimming as seen in several videos by now.

It's cool there are so many options now. Back in 2007 there were basically none. Many of us just started screwing around to figure out what would work.
For lift/lowering, my favorite is using the LLAMS tool but in conjunction with the GAP tool for the best comprehensive approach.