Every truck seems to be a bit different with regard to how much lift you can get from the GAP tool. I forget the exact numbers, but I couldn't get a lot of lift from it. I want to say 35mm. Others have gotten 50mm. I run rods and use the GAP tool to fine tune my height from there.
But...this isn't what Jwestpro was talking about. He's running a LLAMS controller that let's him do on the fly height adjustments. It's still a bit of a rarity at least here in the states but it is a very interesting device. He's nearly convinced me I should have one. Perhaps he'll chime in with the various ways you can use it. I think it's his favorite toy.
Well, I'm pretty sure every guy is born with their "favorite" toy, but the LLAMS is certainly a top item on the rover
I did use the GAP tool first, and found it sufficient actually but you can get more lift by using it and the factory leveling in the correct sequence, I think. As you know, there's either factory first, then choose higher GAP setting, or the setting first, then factory lever. Of course, this does not take into account the hidden factory "extra" height that will occur when a grounding is sensed. That's when it will max out. This can be "induced" by placing something just under the sill, settling back down onto it, and the "extra" feature will engage.
However, the LLAMS tool really is THE BOMB! I'll do a quick test tomorrow from the standard factory lift height, center of wheel to edge of fender. The dial has +30mm and +50mm and a special emergency switch for + (more) but I can't recall how much more.
I use the +30 in town a lot to help the tires wear more evenly and roll normal height to -20 on all interstate travel depending on the conditions. With the 2" spacers this thread was started with, I'd probably never run -20 on the highway though because of the reduced up travel for those random dips and lifts in the roadway at speed.
