The 2010 GMC Savana has a 4-speed automatic.
The 2010 GMC Canyon has a 5-speed manual.
The 2010 GMC Acadia has a 6-speed shiftable automatic.
The 2010 GMC Terrain has a 6-speed shiftable automatic.
The 2010 GMC Yukon has a 6-speed shiftable automatic.
The 2010 GMC Yukon-Hybrid has a 4-speed automatic.
The 2010 GMC Savana-Cargo has a 4-speed automatic.
The 2010 GMC Sierra-1500 has a 4-speed automatic.
The 2010 GMC Yukon-XL has a 6-speed shiftable automatic.
The 2010 GMC Sierra-3500HD has a 6-speed shiftable automatic.
The 2010 GMC Sierra-1500-Hybrid has a 4-speed automatic.
It's worth about $13,000. See quotes at http://www.edmunds.com/gmc/sierra2500hd/2006/index.html