[blykins]

You can get close with a regular Windsor block, but it involves using an offset ground 400M crankshaft. You can also use a 4.100" Scat/Eagle crank and get within a few cubic inches of 427 depending on the bore.

If you go this route, you're looking at machine work, a crank, rods, pistons, rings, bearings, etc.

If you want to go the aftermarket route, then you start with a Ford Racing/Dart/World block, 4.125" bore, and throw a 4.000" stroke crank in it.

I'd be happy to discuss this at length with you if you wish. I've done it both ways and can give you the pros/cons of each. Either way, you will not have a true 427 FE in the car, so there are less expensive ways of getting big horsepower out of a 351W.