I assume this is local legislation? Curious by why not?
Ultimately what are you trying to achieve? Is the vehicle used off road?
Longer shocks should allow more total wheel travel, although without relocating the upper mounts, you will actually be gaining some droop but getting slightly less up travel/compression. As the shock is more at risk of bottoming out, unless you have fitted extended bump stops, which do limit compression.
The Net gain however should be more travel. What you are finding however is, you now have more travel than the uncompressed length of your springs.
There are several options here.
-Run longer springs. Not necessarily stiffer or lift springs, just ones that have a longer uncompressed length. These should remain seated at full droop. This may end up lifting the vehicle still or impacting road handling.
-Limit the downward droop, such as a check strap or a shorter shock. But of course this will reduce your off road flex gained by the kit in the first place.
-Retain the springs. There are kits for doing this or simply strap/tie the top of the spring to the upper spring seat. Depending how far the fall out, cable ties might work, jubilee clips for more strength or even small exhaust clamps. This too will limit downward travel however and in some situations will try and pull the wheel up as the spring is being stretched. If it stretches the springs a lot it may also damage them long term.
-Fit some kind of relocation device. i.e. allow the spring to fall out by retaining it at either the top or bottom and have some device to relocate it again. However you've said this isn't allowed. And ultimately may not be the best thing for off road ability.
-alter the spring seat to make the distance less between the upper and lower at full droop. You can do this by adding spring packers/blocks. However this will also make the vehicle taller when rested by the same amount.
-Alter the upper shock mounting point so that you can attain full up travel and allow only the down to not exceed the spring length. In theory you should be able to increase total travel over stock, but this may not be easy to achieve and may require fab work.
Are you sure you are getting enough droop on the front for the spring to fall out? Typically the front end flexes a lot less than the rear, even on a Disco2. The rear Watts setup also tends to flex less than the A-Frame on a D1/RRC or Defender.
I'd suggest the springs you are using are not appropriate as a first course of action.
TBH I don't know if the D2 uses the same springs as the D1/RRC/Defender does, as in the same physical size. If so, there are lots of springs to choose from, just select the spring rate and length that suit what you want to achieve.
https://www.flatdoguk.com/search.asp?types=FD+SPRINGS
If the D2 spring isn't common to the other models. Then you may have to look at an alternative options though.
