Since you're already dealing with Rock Auto, I took the liberty of looking up the correct tank for your truck.. Here's a link to that tank.
https://www.rockauto.com/en/moreinfo...A73fvFtsSqeANb
It's made by Dorman, a line of parts that is available at most any local auto parts store -- Napa, O'Reillys, and most local "Mom & Pop" suppliers..