[Keithc8]

Be very careful with sleeved 427 FE blocks. Most do not do them right or know how to do them right. Like Berry said it is all about how they were minstalled and why they were installed. Did it have a cylinder completely blown out or what. Must have a step at the bottom in my opinion to hold the sleeve in place. I feel that there are even certain ways to drive the sleeves in so that you do not crack the block.
Make sure you are buying it cheap enough to fix or that they will stand behind the block.
Good luck, Keith Craft