If anyone is interested, this van was for sale a couple years ago. Here is the link to the ad (has pics), and it confirms that it is a Quigley conversion for Roadtrek.
http://www.rvloco.com/forum/showthread.php?t=56778
Nice van.
I have communicated with the previous owner of this van ( ExPo member -
XtremeOffroad4x4). It was already lifted when he purchased it, used. It was originally a Quigley 4x4; but Quigley did not install the Fab Tech "Bracket Lift". That was done by a 4x4 fab shop in Texas. The owner was not sure which shop did it.
Quigley does 4x4 conversions on the Roadtrek vans (3500's), because the 3500 vans are not available in AWD (4x4). Quigley uses 2500 (8 bolt) Silverado suspension parts for their 4x4 conversion. This may
not be the same parts that will work on a factory AWD Chevy van.
As for the discussion on the torsion springs, there are only a few differences between all of the Chevy Torsion Springs.
A) Length
B) Diameter (thicker is stiffer).
C) End-geometry (hexagon) and clocking.
The keys can be different, in that the clocking of the hexagon can be different in different keys. I suspect that a 1/2-ton key and a 3/4-ton key may be different also (or, they might be identical parts).
As the Chevy van gets loaded with equipment (weight), they carry more weight up front than the trucks. This is due to the longer wheel base and most of the storage area being mid-body. For this reason, the vans tend to need stiffer springs up front.
The Chevy suspension does have a hard stop, for down-travel. It is under the upper control arm. The up-travel limiter is a squishy bump-stop that acts like an overload spring (at least on the 3500's). If the torsion bars are cranked to the point that the shocks have reached full extension (maybe by the previous owner), then cranking more will not gain any lift, but it will ride much more harshly.
It is easy to check if the shocks are limiting the down travel.
1) Measure from wheel-center to fender before starting (baseline ride height).
2) Jack up front, under frame, until tire is off ground.
3) Measure again as in step
(1). If there is a difference, then you have some down-travel and it was not completely limited. Torsion bars should be able to provide some lift.
4) Loosen and remove the upper nut on the shock.
5) Measure again as in step
(1) & (3). If there is a difference from step 3, then the shock was also limiting down-travel.
6) The upper control arm should now be resting against the down-travel stop.
Note: I have a 2008 Chevy 3500, that I have been working on, to get a lift. The 3500 van knuckle does not have the same geometry as the 3500 truck. The upper & lower control arms are spaced further apart, and the steering geometry is also different. It is possible the AWD van is the same as the 1500 truck or Suburban geometry, I do not know.
