You have the option of "winding up" the front torsion bars, or in the best world (depending how much they were adjusted when installed, so you don't max out the adjusters) you would re-index/respline the torsion bars in their adjusters to give yourself a bit more adjustment.
If you are mechanically minded, both could be done at home, but you will need a wheel alignment after adjusting the ride height, so I've always just gotten my alignment shop to adjust the torsion bars + align for me.
You need to take into account leaving appropriate room for the front bump stops, seeing if your upper control arms contact your new shocks (Can happen with the big bore shocks, either grind out the lip on the UCA or purchase aftermarket control arms which also allow more down travel and better alignments), as we as ensuring your CV's aren't at a silly angle.
A Minimum 10-15mm gap between your UCA and bump stop is optimal.
The procedure is detailed in the Nissan Factory Service Manual ( have a google to acquire a copy ), and a few guides are on the navara forum (Previously navara.asia)
Thought I would make a Maintenance and Tech guide for torsion bar adjustment as it is a common question on here: DISCLAIMER: I am no certified mechanic, do this at your own risk. All work on vehicle suspension should be done with no load on it and the car securely raised up on jack stands with...
www.navaraforum.com
The question is also asked, what rate / load leafs do you have in the back? If they are a heavy duty/constant load pair, your rear will always sit higher unloaded! And as with most load carrying utes, you will always have an element of "Rake", with the rear higher than the front, allowing for maintenance of ride quality while loaded and handling characteristics.
Or there is the style of "Cali Lean", where the front is jacked up much higher than the rear, an American phenomenon based off race trophy trucks, allowing for jumps to be taken at speed.
