Limelight beat me, but same thought for me, how is it different robbing air and fuel between 5 & 7 and moving it to 2 & 4? Either way you have 2 cylinder firing sequentially together. Each way the sequential cylinders are on the corners on the intake. Just asking
The #4 is firing it is closer to the front of the crank than when the left bank in to the front? I have heard the gains with NA engines come from better harmonics with the 4&7 swap? I suppose that has an influence on the harmonics.
When I have asked about going with a 4 & 7 swap it was told to me that they see gains it to move heat around on boosted applications. But what they see in NA applications is hit and miss on any kind of gain, and not a brand specific statement. More or less told me if you don’t mind shelling out extra $$ for a 4&7 core it doesn’t hurt, but don’t expect it to put you in front of the feild.