ISUZU D-MAX WITH ARB LIFT KIT

You have to be carefull of the CV joint angle so no more than 40mm.

ARB torsion bars are no better than the stock Isuzu gear and many ARB stockist will tell you you don't need them.
Many blokes are running around with Bullbar and winch and stock bars wound up a little.
The std ride height at the front is around 320mm from the top of the rim to the underside of the flare. So, this is your starting point for gauging lift amounts when winding the torsion bar adjusters. Do when weight off the susp though. If altering from original height, either upper or lower the camber and toe in changes and this will evaporate your tyres if not aligned correctly.

If raising the vehicle, the 320 really can't go past 360 or as previously said the cv angles are too great for any length of life.

If all stock parts on the suspension etc, then the stock shock absorbers will not be requiring a change because you haven't gone outside the normal operating parameters.
However, the stock shocks at both ends when new, will pass a roadworthy, but don't in any way perform well as shock absorbers and ride control devices.
An amazing difference is felt with suitable shocks at both ends.
Better to have the rear a bit higher for when load carrying.

Ross M

has the front dropped? Or is the rear now higher by comparison?
As mentioned by others, torsion bar suspensions (D-Max, older Navara, Rodea, Ranger etc etc) cannot be lifted very far (50mm is the limit IMO) BUT they can be very easily adjusted to retain ride height after fitting heavy accesories such as winch etc

I'm sure the installing ARB dealer will be more than happy to explain and adjust your suspension - this is part of the back-up service they provide to thier customers