Why would my wagon be missing after new plugs put in?

Misses at high speeds, and rough idle.

 

After learning the hard way we learn not to assume anything. Sooo,
1. Why did you decide to change the plugs?
2. Did you gap the plugs to the proper gap before installation?
3. Could you have cracked one of the plugs in the process of tightening it?
4. Did you rotate the plug wires to break the seal before pulling each one off?
5. Do you know how to check the wires for open wiring?
6. Did you replace the plugs one at a time?
The answers to the above may help to possibly determine the cause for the miss & rough idle problem.