Fitech/crossram project

I think maybe what the dams do is dampen the pulses across from the cylinder that's firing since it's such a large plenum. Could be reversion or contamination with the intake charge maybe? I dunno, I'm not a fuel system engineer.

The diagram in the old DC book stipulates installing the dams at the far ends by the #1 and #8 cylinder and specifically says to only put them in those two spots. Those two cylinders are the furthest from the throttle bodies but are sequential in the firing order.

The more modern sophisticated cross rams like on the SS/AH cars don't have as large a plenum area, they appear almost inline like a tunnel ram and are only staggered slightly.

You could make the case the later Magnum barrel intake is similar but those only had one throttle body.