Which engine to look for?

[C20-67_N_MO]

Looking for one of the LSx engine family that support the V-8 to V-4 cylinder cut out function.

So my question is what year and model vehicle would these engines orginally come equiped with? Hoping these would be the 6.0 liter engines for performance for my heavy 4x4 and then on the highway be able to go into economy mode for fuel saving mode.

Thanks for your help in this matter.