Old School TM7 versus the New School Victor

On a 640+hp pump gas 496/440 using a 950 cfm 4150 carburetor I lost horsepower on the dyno by going from the plenum shape on the right to the shape on the left. The left plenum only recovered by adding a 2" 4x1 spacer.

https://www.forabodiesonly.com/mopa...-4fa7-4ce4-9d73-e78c510072c5-jpeg.1715623751/