I wrote an email to AirZeroG and asked them:
Other than the interior, are your aircraft modified in any way to handle zero-g flight?
Here is the response that they gave me:
Dear Sir,
Except free floating area cabin configuration, there are very few differences with a “standard aircraft”. The most significant one is installation of Zero-G meters in cockpit and a very simple installation on the wheels to help one pilot to lead the aircraft only in vertical axis, and the other pilot to lead only in horizontal axis.
Out of that, the biggest difference is maintenance program: each parabola performed to create Zero G onboard is considered as an aircraft cycle for the aircraft and its engines, and maintenance adjusted accordingly. Such consideration dramatically increases maintenance costs of the aircraft.
Kind regards
Gilles GOMPERTZ
I would say that if there were a fuel system difference they would say that is more significant than G-Meters in the cockpit. I'm assuming based on the response above that the fuel storage/delivery system is unmodified.