It’s the same intake for the early 5.7L and the eagle, 6.1L port window but they are machined differently. The square port window intakes will need to be port matched to the heads for best performance. I just ran a port matched, profiled divider intake this weekend on my new engine in the Cuda. Ran an 11.12@120.7, 3670lb with driver, 4.30 gear. I had 2 issues. The factory 2005 truck pcm limited the engine to 7000 rpm no matter what we did so I tapped the limiter between 1-2 2-3 and hit the limiter again through the stripes. My converter is too loose as well. It stalled at 5500 with a 236 242 @ .050 112 lsa and .595 lift. It’s just too high. It has 10s in it. Engine is a stock cube 6.1l with ported big valve eagle heads. This is literally pass #4 on this combo and I am whittling it down.