I currently have the Aniversery SS with the stripes and stuff but I used to have a 2000 SS. Both the cas were equiped the same and had about the same mileage. I can tell you there wasnt any noticeable difference. I think GM claims the 02 SS has 20 more hp than the other years but its bs.

 

The 2001-02 LS1 models where given 5more hp then the 98-00 models. That could be what shes talking about. Heres a break down of the changes they made by year.

1998 Chevrolet Camaro: Camaro gets a restyled nose courtesy of a fresh fascia, composite headlamps, and a restyled hood and fenders. Underhood, the Z28 gets a version of the Corvette's aluminum V8 with 305 horsepower, 20 more than last year. SS models get a power boost to 320 horsepower.

1999 Chevrolet Camaro: Traction control was a new option on base models and the fuel tank grew from 15.5 gallons to 16.8.

2000 Chevrolet Camaro: Facing ever-declining sales, Chevrolet's "ponycar" saw little change for 2000. All models now had steering-wheel audio controls. Engines were retuned to Low Emissions Vehicle (LEV) standards, for states that required it. Z28 coupes switched from black to body-color door mirrors. Wheels were redesigned for both the SS option and the Performance and Handling package available on other Camaros.

2001 Chevrolet Camaro: The Z28-based SS package returned for 2001 with high-power V8, functional hood scoop, larger tires, new rear spoiler, and upgraded suspension. V8s gained 5 horsepower and all models got retuned shock absorbers.

2002 Chevrolet Camaro: For its final season, Chevrolet's rear-wheel-drive sports coupe offered a 35th Anniversary Package for the SS version. The package included red paint, dual silver stripes, and special wheels and trim. Newly standard were a CD player and automatic transmission for V6 versions. Pontiac's Firebird shared Camaro's design and also retired after the 2002 model year.

 

It's the cam from the LQ4 engine - a truck cam. It gains quite a lot at the lower end of the curve, making the torque a little less peaky. Peak output isn't everything.
The 35th LE was exactly the same as the SS/Z28 as base, but had the option of the SLP exhaust (rated 335hp), or exhaust and airlid (rated 345hp). Real gains are smaller than that.

 

I've seen 98-00 f-bodies run the LS6 intake and put numbers down like 01-02 f-bodies. This is even with the smaller injectors of those years. The cam change was about economics. One less part for GM to have made and stock and it definately didn't hurt performance.

Yes, GM just bumped the power ratings at random to generate sales. Look at the GTO's 350 hp rating as an example. The engine is no different than the 02 f-body except a small true dual system and they dyno in the 290ish rwhp range just like the pre-LS6 intake f-bodies that were rated @ 305 hp.