Gm 12570790 acdelco 217-1617 factory replacement 90mm throttle body. This is the more desirable silver blade found on ls2 and early 07 ls7 engines. This part  is new. It has been bolted on but never ran. We decided to run a larger 102mm. Tuners like the silver blade 90mm rather than the newer cheaper gold blade. Questions please ask. This was put on 05-06 gto 6.0 ls2 and 05-07 corvette ls2 and ls7. In 2008 they went too the cleaper gold blade.