passenger's side tank

[bnoon]

A previous owner removed the passenger's side gas tank and I'd like to have dual tanks on my '86 carbed 305 LWB. Any hints/tips on whether to go used or buy new? Are there larger capacity tanks that would be worth while or possibly updated tanks from newer trucks to swap in place?

BTW, what is the capacity of the drivers and passenger side tanks? Are they the same? I see some 16 gallon ones on ebay, are those stock replacement? I think the most I've put in the driver's side tank is a touch over 10 gallons because I'm still not sure of how far to trust the gauge.

EDIT: Just saw a 20 gallon one on Ebay. Is that the one for my LWB 2WD?