this way is the usual way to connect the cylinders, as this gives an even spread in the exaust pulses.
i have notised that a lot of b series manifolds are paired other then that, and even though it goes against all theories i have ever read, it seems to work.. anyone can shed some light on the theory behind it?
best guess myself is some bargain between the 2 cam profiles wich affects the lenght on the primaries..