John,
Before you commit to buying be sure to check out this supplier. I have used his fuel rails, pumps, in-tank triple-pump hat and many, many supporting items. All stunningly high quality and all cut from billet, no sheet metal anywhere. The pump hats accept OEM Ford Mustang fuel level sensors. Just a wide variety of well thought out and very nicely manufactured products.
Here is the link =>
Fore Innovations
Be sure to check out the fuel pump hats (baskets), fuel pump selection and all the supporting little items he offers that end up being necessary to finish off a system.
The fuel rails for a big block 427/460 style engine will likely end up being a special (I might be wrong) or you may need to source them elsewhere. Irrespective of what you select from him, my experience has been that he offers a best in class product across the board.