The fact that they are underrated. If you think it has 345 hp from the factory, chances are that it is higher than that. I watched a bone stock 2001 WS6 that is rated by GM to have 325 hp put down 325 rear wheel horsepower with under 1000 miles on it. That is around 370-375 hp.
Your 98-00 LS1's will put down 295-305 average rear wheel horsepower while the 2001-2002 will be 300-320ish in stock form. A 99/01 Cobra makes 269-275 average in stock form. An F-Body weighs just about the same as a Cobra. You made a broad statement that has left a lot of info out. What mods does he have? What mods do you have? What races have you ran? Type of racing? Outcome distances? A 99 Cobra will need gears, full exhaust, and a good amount of bolt ons to beat a LS1.
ME:
Engine:
-C&L Cold Air Intake
-C&L 80mm mass air
-C&L True Flow pipe
-BBK Twin 65mm Throttle body
-SCT tuner
-Steeda non-piggy back style underdrive pulleys
Drivetrain:
-MGW shifter
-RAM HD Clutch
-RAM Aluminum Flywheel
-FMS 3:73 gears
-Steeda quadrant, Firewall adjuster, and adjustable cable
Exhaust:
-2.5" Dynomax off road X Pipe
-3" MAC Cat back system w/ 3 1/2" tips
Suspension:
-Kenny Brown:
-Front strut tower brace
-Rear strut tower brace
-Caster plates
-Subframe connectors
-Extreme matrix brace
-Jacking rails
-Torque brace
-Aluminum differential bushings
- Lowering springs(2" drop)
-Bilstein shocks
-Steeda Bumpsteer kit
-All Urethane bushings throughout
Wheels:
-Ford FR500(Custom white centers w/machined lips)18x9 front, 18x10 rear
-Kumho Ecsta MX 265/35ZR18(front), 295/35ZR18(rear)
Brakes:
-Stainless lines
-Brembo rotors
-Hawk Carbon Metallic pads
-"Z-rated" brake fluid
Safety:
-6 point roll cage w/ swing out door bars and 6" welded plates
-Simpson 5 point bar mounted harnesses (both seats)
-Drive shaft loop
HIM:
WS6 package, automatic