I've mentioned this before but Nissan does apply special treatments (Nickasil) to the lining of the cylinders in some engines (SR20DET for example). It may be worth digging into it a big more to find out if you're going to be removing a lining or heat treatment by boring out the stock block.
"The 300ZX Turbo is a dance; it's a song; it's rolling, roaring automotive art. There is no color that doesn't suit it. There is no mood-lifting chemical substance it can't replace." - Automobile Magazine