I will echo the others, there is nothing wrong with the GM Connect-and-cruise style harness (GMPP controller) if you dont want to make any changes etc to the motor! Its good value, and for those who think it can't look sexy, I have products available to make the install clean! We are in the process of releasing mounting kits for model specific LS3 installations, with hidden ecus and harness cleanup. For the universal stuff, we now have a braided wrap kit to clean up the factory supplied harness, comes with tools for install, cloth 3M tape, and mounting hardware and enough sleeve for the trans harness as well. We also have tabs to mount the pesky plastic fuse box on any flat surface!