This info about intake manifolds may be of interest. I am building a 440 that is going into a Charger & the owner does not want to use an RPM intake because of clearance issues with the hood/air cleaner. Will be using the M1 single plane.
The owner has in his collection, M1, T1, T2 & Victor intakes. I measured the plenum volumes out of curiosity. Here they are in cc, in the above order: 1332, 535, 1260, 885. What surprised me was the Victor. Has the highest rpm ceiling, but smaller plenum vol than the street oriented T2. Also, plen vol in the T2 more than doubled from the T1. Then Edel goes to a smaller vol in the Victor. The chopping & changing makes you wonder about the 'science'. I am using a 3/4" floor spacer in the M1 to soak up some of the huge plenum volume.