Disco 2 for RTVs

Im intending to run my 2000 TD5 in RTVs at club level, its currently got what is supposed a 2inch lift all round but the front is at least an inch high than the back so thats the first thing that needs sorting. So I know where I'm heading does anyone know what the standard height from the centre of the hubs to the bottom of the arches is please. I've also just changed the transfer box to one out of a D1 with a CDL but it doesn't have the High Low switch on it, so can I just fit a manual switch inside.

Standard height at the front is 500 +/- 15 mm (wheel centre to wheel arch lip)
Rear is 483 +/-15 mm (10mm lower on air)
Add the relevant 52mm for a 2 inch lift.
I'm sure you can get away with adding a simple switch to tell the system CDL is on or off.

Thats great, thanks.
The diff lock switch is all ok its the high/low switch that's missing.