It's been cloaked in secrecy for months. A GM spokesman says today the company will take the wraps off the new Chevrolet Silverado and GMC Yukon. An announcement will take place in Pontiac. Mark Reuss, president, GM North America, and Jeff Luke, executive chief engineer for full-size and midsize trucks, will present along with Chevrolet and GMC leadership and designers and engineers who developed the new trucks

GM spokesman Tom Wickham says today's reveal centers on the launch of the light-duty versions of the GMC Sierra and Chevrolet Silverado. Flint Assembly, which is undergoing a $328-million upgrade, will produce heavy-duty versions of the vehicles on Van Slyke Road. 

Wickham says "we are not disclosing the start of production for the heavy-duty trucks or other timing related to pre production build units at the plant".Flint Assembly employs approximately 2,800 employees on three shifts of production. Through November, the Flint plant has produced nearly 103,000 Silverados and 40,000 Sierras, this year.