You are right. Curiously, I traded the Silverado HD 2500 Turbo Diesel for a 2007 Toyota Tundra with 5.7 iForce. Why? I needed to tow a 6700 lbs boat reliabily.
I'm convinced it is not a function of input COGS labor. It is a function of GM business tactics.
But why? Why "kill" one of their most profitable lines (light truck/SUV) by putting these products on the market?