At this week’s SEMA Auto Show GM will be emphasizing its ‘green’ performance credentials by unveiling a slew of modified cars capable of using E85 ethanol plus several ultra-efficient sports cars. In amongst the field of concept and production vehicles will be Jay Leno’s modified C6RS Corvette, an 8.2L beast with over 600hp on tap.

To live up to the green image, Leno and motorsport company Pratt & Miller modified the Corvette Z06 to run on E85 ethanol. More than merely a conversion of the stock LS7 engine to E85 capability, Leno’s alternative-fuel supercar is powered by a custom, 8.2L all-aluminum small-block V8 that pumps out approximately 600hp and 792Nm (585lb-ft) of torque.

The engine is built around a custom aluminum cylinder block that was CNC-milled from a single block of billet aluminum. Its cylinder heads, intake system and dry-sump oiling system are stock LS7 components but the bore and stroke dimensions are larger than those of the stock 7.0L motor. Also new are the forged crankshaft, connecting rods and pistons.

Another E85-fueled vehicle GM has prepped for SEMA is the FlexFuel Chevy Hot Rod, a recreation of the hot rods that competed at early drag strips and land-speed venues of the late 1940s and 1950s. The new car is built by GM Performance Division and takes its inspiration from a 1934 Chevy but it’s powered by a modern a 500hp turbocharged Ecotec engine running on E85, petrol, or any combination of the two.