8.7 deck blocks have been available from Ford Motorsports for at least 3 years. The additional 1/2 inch allows a little longer stroke AND rods so you don't wind up with the wrist pin in the oil ring. Note however, the selection of intake manifolds is not large.
Some people can break a cannon ball, in a sandbox, with their bare hands.
Nothing! The point is to build the short block to suit the block that you base the engine on.
If you try to use stock dimension parts (rods, pistions), crank is another issue, on a tall deck block you have made a mistake from the start. The piston/rod assymbly will be too far down in hole...if you deck the block to bring the pistons up, then you have wasted the reason you got the tall deck block in the first place. To build an engine using a tall deck block you need to spec out the geometry (rod length, pin heigth, etc) before swapping, mixing and matching parts. The best engines are built on paper, before bolting parts together.