Here’s an early look at the engine that will power Mark Stielow’s latest Pro Touring Camaro project. This 427ci LS7 was built by Brian Thomson at Thomson Automotive in Wixom, Michigan. As you can see by the dyno chart, it’s an exceptionally potent street machine with more than 700 lb-ft of torque starting from well below 3,000 rpm and continuing up to 6,500 rpm–peaking out at about 810 lb-ft back around 4,000 rpm.

“The goal for the engine was 850 horsepower and keep the drivability that I had in my previous 427 based LS9. We exceeded that goal,” explains Stielow, noting that LS9 engine was in his ’69 Camaro nicknamed “Red Devil.”

The new Camaro is built around a ’67 first-generation platform and will be called “Mayhem.” It will make its debut at this year’s SEMA show and also compete in the Optima Ultimate Street Car Invitational–an event Stielow won in 2010 with Red Devil. Stielow, a former GM engineer in the High Performance Vehicle Parts group, has built 12 Camaros in the past two decades, each time pushing the limit on how fast and agile a street machine can be. This car will likely run the quarter in the mid-11s and pull 1g on the skidpad–comparable to any sports car costing six figures.

In building the LS7, Thomson modified the block with oil squirters and ARP main studs. The rotating assembly is manned by Callies crank and rods and Diamond pistons. The LS9 supercharger received a modified inlet and the drive ratio was increased. Other tricks include CNC-ported LS9 heads and a new cam that has “more lift and duration than an LS7 but still a road-race cam.”

“I’m very eager to drive this car to make sure we kept the drivability and reliability I had before,” sums up Stielow. “It should be cool.”