When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm fortunate to have never had the need to R&R the tank in my Monte Carlo so I have no experience with what you're asking.
Were I face with this issue, I would look into having the car's original tank refurbished. If that's not feasible, I would then see about acquiring a tank, even if it needed to be refurbished, from a nearby wrecking yard that has a return policy in the event it doesn't fit.