Back in August when General Motors introduced the all-new GT2 class Corvette C6.R, it ran downsized 6.0-liter version of the 7.0-liter V8 from the long-dominant GT1 car. At the launch, Corvette Racing program manager Doug Fehan told us the 6.0-liter was just an interim engine. With revised GT rules on tap for 2010, GM was already planning a brand-new engine for its race Vette.

Unlike the 6.0/7.0, which is a ground-up race engine that only shares basic architectural dimensions with the production small block, the 2010 C6.R’s V8 is a new 5.5-liter unit that will indeed be derived from the production engine found in roadgoing Corvettes. In fact, the 5.5-liter race engine will be built at GM’s Performance Build Center alongside ZR1 and Z06 V8s.

Fehan has confirmed that the 5.5 is running on the dyno and will make its race debut at the 12 Hours of Sebring in March. We don’t have any additional details on the new engine yet, although we were told earlier that it is based on the next-generation production small-block, which we expect to see in the Corvette soon.