Only some 283 blocks (58-62, I think) could be safely bored to 4.00", and that was before they had 50 years of water jacket corrosion! And even if you had a 4.00" 283 block, you'd probably have to do some clearancing to handle the larger 327 crank counterweights.
If you want to build a 327, find a good 350 block from 68-85 and use a crank from a 307 or 68-69 327. These are readily available, even some forged models. You can then use 5.7 rods and off-the-shelf 327 pistons.
If it's a 307 crank, it will need to have the large lightening holes filled with metal to compensate for the heavier pistons. Here's a shot of mine after being balanced: