[sperry]

Okay, here's all the relevant text fromt he '04 rules:

14.8 SUSPENSION

...

B. Suspension bushings may be replaced with bushings of any materials
(except metal) as long as they fit in the original location. Offset
bushings may be used. In a replacement bushing the amount of
metal relative to the amount of non-metallic material may not be
increased. This does not authorize a change in type of bushing (for
example ball and socket replacing a cylindrical bushing), or use of
a bushing with an angled hole whose direction differs from that of
the original bushing. If the Stock bushing accommodated multiaxis
motion via compliance of the component material(s), the
replacement bushing may not be changed to accommodate such
motion via a change in bushing type, for example to a spherical
bearing or similar component involving internal moving parts. Pins
or keys may be used to prevent the rotation of alternate bushings,
but may serve no other purpose than that of retaining the bushing
in the desired position.

C. The following allowances apply to strut-type suspensions. Adjustable
camber plates may be installed at the top of the strut and the
original upper mounting holes may be slotted. The drilling of holes
in order to perform the installation is permitted. The center clearance
hole may not be modified. Any type of bearing or bushing
may be used in the adjustable camber plate attachment to the
strut. The installation may incorporate an alternate upper spring
perch/seat and/or mounting block (bearing mount). Any ride height
change resulting from installation of camber plates is allowed.
Caster changes resulting from the use of camber plates are permitted.

D. Camber bolts may be installed providing these parts use the original,
unmodified mounting points and meet the restrictions specified
in 14.5.B. Caster changes resulting from the use of camber bolts
are permitted.

E. Addition or replacement of suspension stabilizers (linkage connecting
axle or De Dion to the chassis that controls lateral suspension
location) is permitted. Traction Bars or torque arms may be added
or replaced. A panhard rod may be added or replaced. Methods of
attachment and attachment points are unrestricted.

F. Camber kits may be installed on vehicles that do not have
McPherson strut type suspensions. These kits may include replacement control arms or other parts that are designed specifically to
compensate for camber changes resulting from lowering the car.
These parts must use the original attachment points.
...

14.11 STX
A. The STX class expands the vehicle eligibility limits beyond those
specified for STS, and adds a limited number of allowed modifications.
The allowances are as follows:

1. All allowances in STS carry over, including street tires, emissions,
etc. except as follows:

...

B. Replace 14.8.E with “Camber kits, also known as camber
compensators, may be installed. These kits consist of either
adjustable length arms or arm mounts that provide an adjustment
to the effective length of a control arm. Alignment
outside the factory specifications is allowed. The following
restrictions apply:

1. On double/unequal arm suspensions, only the upper arms
OR lower arms may be modified or replaced, but not
both.

2. On arm-and-strut (MacPherson/Chapman) suspensions,
the lower arms may be modified/replaced OR other methods
of camber adjustment as allowed by paragraphs 14.8
B., C., or D. may be used, but not both.

3. On swing or trailing arm suspensions, the main arms may
not be modified but locating links/arms may be modified
or replaced.

4. The replacement arms or mounts must attach to the
original mounting points. All bushings must meet the
requirements of 14.8 B. The knuckle/bearing housing/
spindle assembly cannot be modified or replaced.

So it looks like Dean's on the money... you can use links as long as you're not using offset bushings, adjustable top mounts, or camber bolts.