Silversx:
I was told by a guy at toytec that the OME springs don't work well with 5100's set to any lift height. (but will be fine at the 5100's no-lift setting obviously). The OME's don't have enough coil winds to handle being pre-loaded on 5100's set to notch 2,3, or 4. They loose their smoothness and progressiveness.
I currently have stock springs with 5100's all around with the front set at .85. Very happy and looks more natural, it's fine for me but I can understand someone that wants or needs more lift.
Whatever you do I believe your goal should be to add 1" more front lift than rear. Ex. 3" front 2" rear, or 2.5" front 1.5" rear.
I would have to say that my setup feels balanced for the most part but I can tell that the front spring rate is slightly stiffer than the rear. I have a good sense of suspension and handling dynamics, most people wouldn't notice. If I had the front 5100's set to 1.75" with the stock rear springs, it would be really out of whack. Way too soft in the back compared to the front, almost dangerous.
I had thought about the SAW rear coils at 1.5" and setting the Bilsteins with stock springs to 2.5" of lift. Height wise this would be about perfect. The only question mark is how are the spring weights changing in regards to % increase over stock front vs. rear. It probably would be close to good but no way to tell until someone gets data:
The question becomes, with stock springs, what is the spring rate of a 5100 set at 1.75" or 2.5" of lift? And what percentage over stock is that? And when pre-loading the stock springs that much how smooth and progressive is the travel going to be?
We should be careful that the % increase in front spring rate closely matches the % increase in rear spring rate. With the 5100's set to 1.75 or 2.5 it's a guessing game.
Here's some data I compiled: (all lift heights based on 5th Gen not 4th)
Front
Stock oem springs are 500lbs
OME 883 2" Lift 590lbs rate, 18% stiffer than stock
OME 884 2.5" Lift 590lbs rate, 18% stiffer than stock
OME 885 3" Lift, 590lbs rate, 18% stiffer than stock
OME 886 3" Lift 650lbs rate 30% stiffer than stock
Rear
Stock oem springs are 180lbs
SAW 1.5" lift 213lbs, 18% stiffer than stock
OME 895E 2" lift 260 lbs 44% stiffer than stock
OME 895 2.5" lift 260 lbs 44% stiffer than stock
OME 889 3" lift 260 lbs 44% stiffer than stock
Superflex 2.5" lift 218 lbs 21% stiffer than stock
Looking at this data, the 884's in the front and the SAW in the rear would both yield a 18% increase in spring weight and would lift an optimal 2.5/1.5. The other combo that sticks out is the 885 front and superflex rear for a 3/2.5 lift. I discovered that all of the OME rear springs are darn stiff! Great for guys that haul stuff a lot or that tow or have rear bumpers or fridges, etc. For me though, I would want the percentage increases in spring rates to stay balanced front to rear. Hope this helps.