Wet Seal Sleaves In 427?

[UK RUSS]

I have a 427 Side Oiler with a 2" crack in the #1 cylinder
The engine is completly stripped down & has 3 sleaves in it, one of which has the crack in it.
The problem is it has already been bored to 50 over , the sleaves that are in it are very thin , The pistons & rings are custom made & have no markings on them .
Another problem is that with such excessive boring there is no longer the lip in the block that a sleave would normally sit on thus creating a "wet seal" sleave.
I have been talking to a guy in Palmdale who says he can remove the old sleaves and sleave all 8 holes with a thicker ones so I can still use my pistons, and he guarantees all his work
What do you think about wet seals?
Sould I be concerened about having sleaves in all 8 holes?
Should I be looking for a new block?
What are the chances of finding a 427 short block?
and how much $$$???
Any comments are much Appreciated.
Thanks,
UK RUSS