Aftermarket bushings actually aren't allowed in stock class... Unless there is an exception based on age that I am not aware of? You can't delete the A/C in stock class, unless it was a dealer-installed option on your vehicle.
You can do the following:
- Brakes -- Any pads that fit in the stock calipers are allowed. You must keep OEM or OE-replacement brake rotors, though. On cars over a certain age, you can replace the brake lines with stainless steel braided lines, I believe. You may want to confirm in the rulebook, as it has been a long time since I had a car that I was concerned about the brake feel.
- Exhaust -- you can do anything you want *after* the catalytic convertor. The header, downpipe, catalytic converter, etc, all need to be stock.
- Air intake -- you can ONLY replace the air filter itself with a different replacement filter element such as a K&N OE replacement. You cannot modify the airbox or intake plumbing.
- Front sway bar can be replaced
- Shocks -- up to two adjustments are permitted (i.e. separate compression and rebound adjustments). Stock springs must be retained, and the distance between the center of the lower bolt hole and lower spring perch must remain the same as stock, thereby keeping the ride height stock).
- Wheels... Any wheel can be used, as long as it is the same width, diameter, and within a 1/2" of the same offset as stock.
Those are the big ones... The full rules can be found here:
http://www.scca.com/documents/2011%20Tech/2011%20SCCA%20Solo%20Rules.pdf
