Gas tank? for 69 step (early classic SS tank)

[Sequoyah]

A person on a local forum is selling one and has said he's had it for awhile. He said he payed $580 for it originally. He is asking $375 for it. It is brand new (never been installed).

I was just wondering if this seemed like a good deal and more importantly...will it work with my truck. From the early classic site it looks like they come in either an 18 or 23 gallon size and work with either internal or external fuel pump.

*Dimensions (the tank he is selling)

-27" wide
-20" deep
-10" tall



...and the one from Early Classic:



http://www.earlyclassic.com/catalog.aspx

It looks like there are a few differences between the two...can anyone identify if it's 18 or 23 gallon? The seller doesn't know and was going to try and find the paperwork on it. What would you pay for it? Thanks for any help with this

oh yeah...I've posted here and there, but never posted my truck. I'll do that soon cause I know everyone here likes pics although it's not much to look at right now