4 is the number of 767-400s that have the 20/236 configuration, after converting one of the original 5 to 35/200 earlier this year. So, this would be a 1-to-1 replacement.

Don't forget the Boeing strike. Not only will it push back the 787s, CO also has 2 772ERs that are supposed to be deliver in 2nd half of 2009. Who knows what's the status of that now.