Speaking of PiBu:
aviationweek.com
Here are a few interesting tidbits especially about airframe modifications.
Is he referring to the circumference of the nacelles? If so, what changed?
TRACY CASSIL Promoted To Senior VP-International Finance | Aviation Week Network
TRACY CASSIL was promoted to senior vice president of international finance for Cessna Finance Corp. Cassil has served with CFC since 1982 and most recently was vice president of international sales.

Here are a few interesting tidbits especially about airframe modifications.
The aft fuselage section (housing the electronic warfare equipment) was made longer, and the circumferences of the aft lower fuselage, some doors and hatches, as well as wingtips have been modified. Fifteen first-production aircraft will be made in that configuration.
Is he referring to the circumference of the nacelles? If so, what changed?