I think if the Boeing 747-800 is going to be a success an upgrade kit for the Boeing 747-400 must be offered (if possible).
Mainly for the cargo version, the -i version is more in doubt.
The GEnx 2b was tested first time on the 747-100 series inner left engine last monday 23rd of march, the -100 is 1dm shorter than the -800. But the wingspan is way different.
http://www.flightglobal.com/blogs/fligh ... es-to.html
