All FE blocks are the same size, so if a 390 fits, so does the 427... and of course the 428.
There are numerous resources beyond the Ford documentation you are requesting info on. Barry Robotnick has a great book written recently
If your not a member of the Network 54 FE Forum, I'd suggest you start there. Also, Ford factory 427 blocks are becoming more scarce by the day and usually need significant machine work ($$$), so you might look into an aftermarket block.
Also... a big change in the power potential is the availability of 390 engine stroked to 445 cubic inches offering a reliable 500HP. Much cheaper, much easier on the wallet, and looks the same
PS: If you register on the Netwok54 FE Forum, which I think you should do, don't ever call it a 425, and don't ever try and explain the math behind cubic inches.
Note that I switch back and forth between 425 and 427 when discussing the block. 424.96 was the actual displacement of the engine. "427" was what it was badged as so that it would be immediately recognizable as Ford's NASCAR engine.
The "427" is an engine with 4.23" bore x 8 cylinders with a 3.78" stroke from the 390.
volume of cylinder = πr≤h
π * (4.23/2)≤ * 3.78
π * (4.473225) * 3.78
π * (16.9087905)
53.12 * 8
Total Engine displacement of the "427" = 424.96
...just for the uninitiated. I was talking with a guy at the Shelby booth at the Columbus Auto Show (trying to find someone's brain to pick on building my own side oiler) and thought I could say "425" with his understanding...however, he was thoroughly confused; I had to do the math on the spot to remind him.