The early 5.7 has a coil on one plug and a plug wire from a coil on the opposite side for the second plug. My understanding is the second spark is mostly wasted, firing on the backside of the power stroke. It's purpose is mostly EPA related.
There is apparently a kit to to fire both plugs together.
Kevin
Its called don't cross over the wires, just coil up the extra length and stick it in the hole next to the coil. Jacobs makes a short wire specifically for this, probably the "kit" you are thinking of butt it is very easy to do even with the stock wires.
