FilthyPoncho

Answer to all this is up above. Perhaps I should've quoted myself or put it all in one post instead of making it confusing for everyone.

Part #111209. You can find it on the BDS website under accessories, but as I said in my previous post I would suggest having a full leaf added instead of the BDS. The leaf is smaller than I thought, only extending a few inches past the overload spring. When adding weight to the truck this setup puts awkward strain in the middle of the two longer leafs so I would suggest adding a full length leaf. If that makes sense. Here's a photo of it added.

I stuck with factory. Eibach states the lift is between 1-3" depending on application, but the installation instruction sheet has the lift numbers I mentioned above.

2015 LTZ Midnight Edition with Eibach Pro Truck Kit set at 2.5in level with BDS add-a-leaf springs (just go to your local spring shop and have them add another leaf, don't bother buying the short BDS ones like I did) sitting on 295/65r18 Duratracs on stock wheels.

I've had the Eibach kit for about 9,000 miles and it's been a good improvement over stock struts and shocks. Originally I had a BDS leveling kit installed but I was having issues with bad tire wear (nothing to do with the leveling kit since they started wearing poorly prior to install) and I narrowed the problem down to either worn struts or just terrible tires, plus I was at 60,000 miles so I figured it wouldn't hurt to replace the front struts and shocks. At first the Eibachs were extremely rough and the front nearly sat level with the rear even with an additional leaf spring, but it quickly settled and the ride became a lot better. Turning is so much nicer with less body roll and it takes large and small bumps well, although the added leaf makes washboard worse. The springs are heavy duty and made my repair shop a little nervous when they tried to compress the springs during install. I have it set at the lowest level (2.5 in) but you have 3 more options, one for a 3.2 in lift and the two highest settings for heavy duty situations like an after market bumper or snow plow. When everything needs replacing again i'm certain I'll go with Eibach. If its time to replace your struts and shocks and you want a level at the same time i would definitely go with the Eibach setup, and they look better than the stock Rancho.

I installed Eibach pro-truck lifted springs in the front set at 2.5 inches with an add-a-leaf in the rear on my '15 half-ton. Just put on 295/65r18 Duratracs on stock z71 wheels yesterday and it sits 39.75 inches front and 41.25 inches rear which is perfect for towing a trailer and having the truck sit level instead of rear sag. Here are some photos of the front wheel well at full turn with no rubbing whatsoever. I'll have more photos of the truck soon but I need to wash her first. This is my first ever post and have spent MONTHS researching leveling kits, lift kits, and tire size on these forums so i'd like to say thank you to you all!