Van's has been the consistent "lower price provider" for fuel tanks. IF you notice the part number of the tank you need, no matter who sells them, they are ALL the same part number, so they are ALL the same tank. For different prices.
In the earlier days of tank internal coatings, some would disintegrate and clog up the fuel filters. The absolute best re-finish is the Gas Tank ReNEW process, where they cut the tank apart, coat it, and then weld it back together. BUT that's expensive and is usually done on tanks for which there are no repros available.
You can also look at
www.rockauto.com for a reference price, but I believe that Vans has free shipping in their mix, too.
Reason I've been looking, too, is that I will need a few tanks, all the CR20 I believe. They are usually less than or right at $300.00. For my '67 Newport 383 4bbl and my '70 Monaco 383.
There's a thread in here about changing the tank and all of the fuel lines.
As mentioned, you'll be $$$ ahead to go ahead and replace the tank, rather than trying to make the old one work a little bit longer. Consider a new tank an INVESTMENT in future driving peace-of-mind. Just shop for the best total price! As everybody's re-selling the Spectra Premium tanks and such.
CBODY67