so when I did mine 14 months ago I THINK i saw the DRVR and PASS markings on the springs but I can't really confirm. I'm still crippled at this time so going under truck is not an option right now (perhaps Tyler will get you an answer faster than I can go under the truck)
Last I measured when I did the last oil change (last November, I believe) I was sitting at around 39.5" all around (measured via middle of the fender all the way to the ground, passing the center of the wheel).
For the Rebel HD coils, it is listed to bring 1" of rear lift with up to 500lb of constant weight, which is pretty on par with my truck even though I'm pretty sure my rear has slightly over 500lb constant. With your weight in the rear it does make sense that you are close to what I have in the rear but I'm sure you don't have more than that lol.
My rear axle weight as outlined:
GFC ~295lb
Drawers ~208lb
Drawer contents with camping equipments ~50lb max
Camper electricals (lights, charger, wiring, etc) ~40lb
Total weight without my fata*s ~593lb max.
Total weight with my fata*s ~800lb
One thing to note: even with my fata*s upstairs at camp the springs don't really compress and drop in height.
Now, with the Eibach option, you need to find out the weight capacity of the springs. Lift height is one thing, but it's useless information without knowing what is the maximum weight capacity those springs can handle before compressing.
Alternatively, you can go with the Ironman 4x4's rear springs:
IRONMAN 4X4 coil springs increase ground clearance, accommodate larger wheels and tires, and ensure a stable ride. Versatile for daily driving and off-road adventures on pavement, gravel trails, or rock crawling, they offer various load choices to enhance performance and durability for any...
ironman4x4america.com
2" in the rear with up to 660lbs.
I ran the medium duty 3" ones (up to 880lb) on my 4Runner before with RTT (300lb+), drawers, fridge in the trunk, and stuff and they really gave me 3" in the rear with all the weight and still rides great.