Nice chrome gas tank

It's a top mounted tank that doesn't have the tunnel underneath. I have needed a tank like that in the past. I have a frame, now that it might work on.
I just can't justify the dollars when I have so many other projects.
I need to stay away from Ebay, too. Maybe I can try lottery tickets...
Its a nice tank . Recieved mine a couple weeks ago. The petcock was trash. Cheap pot metal. Spigot was broken on delivery. Seller sent out a new replacement with a section of hose . Different that what originally came with the tank. Far better quality. No complaints here.
My question was : Will the opening in the rear of the tank sit down over a frame that is 8 inches wide?
It sounds like it would sit on top. Thank you so much for measuring and reporting back.
I don't feel so bad now that someone else bought it.