Exactly...the gas tank is the last of his concerns
if he found a way to SAS a 2005 IFS setup with RACK AND PINION steering when there wasnt even the hint of a kit available yet, throw a Ford 9" under the rear of a Nissan and overcome all of the other challenges of an SAS from scratch...
then I'm pretty sure he and his shop could work around a gas tank problem. He could just as easily buy a fuel cell or something.
there are options.