You can modify any components in the air intake BEFORE you hit the airflow meter. Meaning that you can put on a cone filter, pop charger, ect. But once you hit that afm, gotta use the stock parts. Sucks for the Nissan crowd cause they are usually near the airbox/filter. Hondas are near the intake manifold. You can build a cool air box around the cone filter but you can't drill holes in the bodywork (you can't use any hole that isn't a stock hole) and you can't ducted directly into the airflow to get any kind of rammed aired effect.

Suspension, you can run shortened shocks and adjustable coilovers but the coil over collars cannot be permanantly attached to the shock tube/body. The suspension pick up points have to be the stock points with control arms being stock, (no changing or reinforcing) but the bushing material is open. Read into that what you want...there has been much debate over what the means. But delrin, poly, and spherical bearings have all been used. Remember that you can't weld in spherical bearings per the rules.
Camber plates are legal, and well as any sway bars you would like. Anyone else out there.............jump on in.

Tristan Smith
ITA 1989 Nissan 240sx
ITB 1978 Datsun 200sx