Dave, I am pretty sure springs are allowed in Street Prepared.
As far as I know... ANY intake modifications are allowed, any exhaust modifications are allowed, the ECU may be reporgrammed, any ingition modification is allowed, suspensions must maintain original mounting points but shocks, struts and springs are replaceable with aftermarket alternatives... Strut bars are allowed as long as they only travel transversely from strut/shock tower to strut/shock tower and are bolted in.

Basically, ANY bolt-on. No internal modification of the engine unless allowed by the update/backdate rule. I would not worry anyhow, not like you're competing divisionally or nationally where people will ACTUALLY protest.

I just read up...
14.8A
"Ride height may only be altered by... the change or modification of springs... Springs must be of the same type as the original... and must use the original spring attachment points"

omitted the useless info

FLNeonRT you are definitely in DSP.
-Shawn