Reiter Engineering are well known for their Lamborghini race cars (Notably the Diablo GT, Gallardo GT3 and Murcielago R-GT) but recently they teamed up with SaReNi to produce the Camaro GT3. Powered by a Katech tuned Chevrolet 7.9 V8 mated to a Hollinger 6 speed manual the car produces 650HP and 590 FT-LBS of torque, however the engine is detuned down to 500HP in racing spec.
The car also features a more aerodynamic front bumper and carbon splitter (and canards), blacked out wheels and a huge GT racing wing. The Camaro GT3 costs $250,000, making it one of the cheapest modern GT3 cars. The Camaro GT3 currently campaigns in various GT3 racing series including the ADAC GT Masters and the Blancpain GT Series.
Specifications:
Body: 2 Door Coupe
Engine: GM Katech 7.9 V8
Power: 650HP (500HP in Race Spec)
Torque: 590 FT-LBS
Weight: 1290 KG
Drive: Mid Engine Rear Drive
Transmission: Hollinger 6 Speed Manual Sequential
Well, I did some more research on the engine and while it's a GM engine, it's tuned by Katech. I haven't been able to find out which engine it is exactly but my guess is that it's a tuned version of the LS7 (Used in the Corvette C6 Z06 and 5th Gen Camaro Z/28)
Also have you seen the interior of the Camero Ss? In GT6 or 5 it looks like a GT3 car interior it's just missing that wing and the fact that it is mid engined for some reason.