You have an LS-based engine in your truck. VVT is variable valve timing, and DOD is displacement on demand. Both are ways to boost fuel economy in late model engines. Performance-wise, neither of these are engines anyone would build, but I personally would LOVE a 2011 Chevy Silverado. Nice trucks! Drive it and be proud! I like Dodges too, but if I see another HEMI sticker on a truck, I swear I'm gonna puke!