More proof of the Z06 lapping the N-ring in 7:40. Here is a German article stating the times for the Z06. Note how they say "Z06" and NOT "Blue Devil"
http://www.imageark.net/image.php?id=122345
Translation:
“Record was not in
Straight from his GT1 class victory at Le Mans, Jan Magnusson shortly thereafter at the Nuremburg Ring came up with speed. With the Corvette Z06, should the track record fall – great advertising for the new sports Corvette. However, more than a good 7:40 wasn’t in it. The North Loop record for Series Cars is still held by a Donkervoort RS: 7:18:01.”
It is funny how the Germans are trying to send the message to the public that 7:40 is just a "Good time", and that a better time just "wasn't in it"..

. Hey, atleast they are trying, right?..
Also,
Found this over at GM LSX Syndicate: Another indication of the Z06's aweosme lap time and they state the driver, also.
7:28 --- Porsche Carrera GT, Walther Röhrl, Autobild July 2004
7:32.4 -- Porsche Carrera GT, definitive time by Horst Von Saurma
7:32.5 - Gemballa Porsche GTR 600 EVO, Wolfgang Kaufmann (2001)
7:36 --- Porsche Carrera GT, factory test driver Walther Röhrl (2002)
7:40* -- Porsche Carrera GT, *estimated time on cold and partially wet track (2003)
7:40* -- 161.217 km/h – Corvette Z06, 505 PS/ 1419.7 kg (estimated), Jan Magnusen
7:40 --- Mercedes Benz McLaren SLR, Klaus Ludwig, Autobild July 2004
7:42 --- Radical 1500 SR3 (2002)
7:43 --- TechArt GT Street (2001)
7:43 --- Porsche 996 911 GT3 RS, factory test driver Walter Rohrl, MOTOR Magazine
7:43.5 - Lamborghini Murcielago (Autocar magazine, 2002)
7:44 --- Pagani Zonda C12S (07/2003)
7:45 --- Gemballa Porsche GTR 600 (12/2000)
7:46 --- Porsche 996 GT2
7:46 --- SHK Porsche 993 GT2, 652 PS (1999)
7:47 --- Porsche 996 GT3 RS, 381PS (996) (2004)
7:49 --- Porsche 996 GT3 Cup
7:50 --- BMW E46 M3 CSL (08/2003)
7:50 --- Blitz Supra, 750 PS, Herbert Schürg (1997)
7:50 --- Honda RC30, Helmut Daehne (1993)
7:50 --- Lamborghini Murcielago (06/2002)
7:52 --- Gemballa Porsche 911 Le Mans (1995)
7:52 --- Lamborghini Gallardo E-Gear (12/2003)
7:52 --- Mercedes Benz SLR McLaren (06/2004)
7:54 --- Porsche GT3 (996) (2003)
7:55 --- Caterham R500 Superlight (2002)
7:56 --- Ferrari 360 Challenge Stradale (02/2004)
7:56 --- Porsche 996 Turbo
7:56 --- Honda NSX-R - Motoharu Kurosawa, Best MOTORing
7:56 --- Chevrolet Corvette CE Z06