Installed and took my buddy's full weight 6th Gen to the track a few weeks ago.
Current Mods are: LT2 (Non Ported) Intake Manifold, Cat Delete Pipes, Rotofab, E85, and ECM Tune ONLY.
He went 11.45 @ 121.50MPH. His previous best in pretty similar conditions was 11.98 without the LT2 IM and Cat Delete Pipes.
I did not have to adjust the tune at all when I added the LT2 IM from the stock IM. It stayed 12.8ish AF.
Pretty impressed with this IM vs. the more expensive alternative. Good bang for the buck.
https://gwatneyperformance.com/cart-share/kNGeE/ref/2/