OME makes lifts from stock hight up to 3.5" based on the loads specified below. Un weighted, they could be as high as 5". However, the resulting lift depends on what accessories you cary. Armor, Bumpers, Winches, Tools, and Trail Spares will all weigh a lift down.
If you have a Lexus LX450, the stock suspension is much softer than the 80 series Toyota venison. The softer ride tends to provide more lean around corners and a lot of people don't like it. Just changing to the stock height OME will make a great improvement.
The nice thing about an OME lift kit, is that once you have a basic OME lift installed, you can swap springs as you add armor and accessories to maintain the same basic lift height with the extra weight.
So for the OME you really need to decide 0" lift, 2.5" lift or 3.5" lift. Higher lifts can be accomplished using heavy springs in un-weighted situations or by adding spacers, but the higher lifts take it out of the OME design window.
From Christo Slee's Web Page:
Since this is not just another lift kit, it is essential to match the spring rates to the weight of the vehicle.
Here is a an example Rule Of Thumb first posted by Beowulf
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OME Springs:
General rules:
unladen 864=5" lift or 2" w/400 kg load (20mm wire)
....... 863=4" lift or 2" w/250 kg load (19mm wire)
....... 860=2" lift or 1.75" w/a gas tank (18mm wire)
....... 850=2" lift w/some weight(dual batteries etc)
....... 851=2" lift w/bar & winch, dual batteries, etc
....... Stock springs 16mm wire.
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OME shocks
............. Open ......... Closed
............ length ........ length
N70 ......... 614 .......... 354
N71E ........ 620 .......... 370
N74E ........ 620 .......... 370
N73 ......... 614 .......... 354
N73L ........ 667 .......... 387
N74L ........ 667 .......... 387
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Here are a couple of useful Tables. Note that the J Spring is the same basic spring as the non J, but 1" taller.
This is from Slee's site on springs, expected lift WITH expected weight load.
Table 2 was compiled from information on the Cruiser Outfitters Site
Note that an un-loaded 864 lifts about the same amount as an unloaded 863J (both of which are about an inch or so higher than an 863). It takes twice the weight to lower 864's to any given height as it takes to lower 863J or 863. That's because the spring Diameter on the 864 is wider.