Unless the hole is within 1/2" of the top or bottom of the cylinder, go ahead and sleeve it. What caused the hole- - - -maybe a broken rod or something similar? That's a very unusual failure unless something comes totally unglued.
Have your machinist use a heavy-duty sleeve, one with a 1/8" wall thickness, not 3/32" like would normally be used to recondition a cylinder. I've sleeved race engines with holes a couple of inches in diameter in a cylinder, and got normal performance out of them.
230's have a nasty habit of developing cracks in the block along the lifter bores, so if you've got a block that's OK in that area, better hang onto it and patch that cylinder.
Jerry
