How do I know if my car fits under the "some cars are able to update/backdate engines?

"Street Modified – The top of the “street” categories, Street Modified allows
anything from Stock, Street Touring, and Street Prepared and just about any
engine and drivetrain configuration as long as the engine manufacturer matches
the body manufacturer (see Solo Rules for details). Four-seaters (BMW, Corolla,
Civic, Integra, Neon, Supra, Talon, VW, etc.) run in SM and two-seat sports cars
(Corvette, CRX, M Roadster, Miata, RX-7, MR2, etc.) compete in SSM. Carbonfiber
hoods, cams, turbo/supercharger kits, etc are welcome, too."

CSP
The original SCCA® “street” category, Street Prepared allows
any carburetor/fuel injection system and any ignition system. Turbo/supercharger
hardware has to remain standard, but aftermarket boost control
systems/programs and intercoolers are allowed. Exhaust manifolds and systems
are free. Emission controls are not required for competition, but no internal
engine or transmission modifications are allowed beyond factory specs (no cams,
hi-comp pistons, ported heads, etc). Some cars are able to update/backdate
components like engines, brakes, etc (See Solo Rules for details and specifics).
There are no limits on wheels sizes or DOT tires; racing springs and shocks are
the norm.