Caution: California emissions testing will not look kindly on a tank replacement that is not CARB approved - IF the emissions testing facility catches it the vehicle will fail the test. This is why SMB gets big $$ for their Transfer Flow tank and its CARB approval sticker.
Caution when selling the vehicle is also in order if the new owner registers the vehicle in an emission testing locality. I have found that California inspections are actually far less thorough than some other states/locals. If the new owner is not aware of the fuel tank change and gets a big surprise when registering, issues will arise.
Just a heads up / eyes open.
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com