I bought an 05 CTS with 100k miles on it. I know its time to replace some parts, and I would like to address some issues at the same time. I want to know if anyone has really taken this engine to the grindstone. Like knife-blading the crankshaft, balancing the rotating assembling, adding oil drain holes or pin oiling ports to the pistons. I am sure I could get custom pistons made, I think Ross could make them for me. But I would like to use the existing rotating assembly. Has anyone done any port work or valve work to the heads? Do the LLY DI engines have the same oil consumption issues? Has anyone thrown a set of their pistons into the LY7? It will be a while before I have the money for this rebuild, so I want to get as much information as possible before I contact a machine shop. I know I am getting the RX Ice-olator intake manifold spacer, RX oil catch can, Volant cold air intake, and drilling out the PVC. Probably will do all that when I replace the spark plugs, which I need to do. And another thing I have been wondering about is updating my 05 programming to the 07 numbers. I have heard of people doing this, what sort of gains can I expect? Im not expecting huge horsepower numbers, I want a better running machine. A smoother idle, and easier shifts, perhaps eliminate those rough downshifts. Im committed to making my CTS a performance machine that will last me a good long while, and I could use any help I can get. Let me know what you guys have done, and how much it helped. Or dont, its your choice.