With my Co's Vol 2, 7.20.4, dated March 29, 2004, it does not specifically mention that for the 800, you will get 27K.
Are you referring to the section titled Structural Limit Protection, where the EEC provides N1 and N2 redline over speed protection?
The inferrence here is that these limits are the max N limiting power the engine could produce which is 27K (assuming not EGT limited).
If the airline uses an engine limit of 26K, then could maintenance allow the EGT margin to deteriorate further to a 26K engine, and not a more restrictive 27K engine?