A few WCC owners have already upgraded their fuel tanks. DocDirk has recent experience assembling his car PM him for details. My understanding is if its the original plastic fuel cell, it's slid onto the trunk shelf and strapped in with 2 steel straps. Its a really tight fit I understand. The tough part is getting the fill neck rubber hose off to slide the tank out. Below is ByronRace's tank , his pump plumbing is different however it's the RJS plastic tank that was typical on the WCC. Some have created a tank that drops down several inches below the shelf to gain more volume.[
Here is an aluminum fuel cell cwmcobra had installed.