I know that the 425 block is lighter.. meaning it has been shaved down in "safe" areas... and I also remember reading that the 425 crank isn't as strong as the 472/500....

But my question is... now that I have decided to stick with my 425 for a while... lets say in the future, I want to pull the engine.... would it be possible to get a 500 crank and put it in, then get the block bored out... 500 heads etc.... and then my 425 will be a 500?

That would be nice, as I would be able to save my 425... and the engine will be origanal to the car.... would there be any real bad side to running a 425 converted to 500 over a 500 from the start?

You can't go anywhere near a 4.3 bore on a 425 block. I believe the max you can go is 80 over which is 4.16 but thats probably not a good idea if you want it to be rebuildable next time. It might even be .060 instead of .080. This is just something I heard from someone on here a long time ago, maybe it was Angela Desmond - she's building up (probably finished a long time ago) a 425 as well but hers is way more serious than yours.