When thinking about oversizing an engine one must wonder that the engine was originally designed by the manufacture to perform under the normal engine bore sizes...When over boring you weaken the block considerably, compromise the heating systems in some cases, and your asking that block to perform with a much greater HP output over stock with thinner cylinder walls, etc..
That means increased heat, stress, with less metal or alloy in the engine block to support the increases...Hmmmm?
Maybe just obtaining a bigger manufactured block would be your best bet, for strength, longevity, and safety rather then trying to bore out a smaller block... I personally would be a little weary to do a large engine bore job on any manufactured engine block...
Does that make sense anyone?
Then again when you size the Chevy small blocks, a 283ci SBC has the same block demensions as a 350ci and or 383ci SBC if I am not mistaken...If that is the case you could then bore out the 283ci block to the 383ci block size without structural compromise.. That to me would be the only safe and reasonable engine bore to do... Same theory applies to the Ford blocks... I was thinking the same with the 1uz's like the 4.0l to 4.3l to maybe 4.7l...????