I lost a bearing in the bottom end of my b18 and am planning on rebuilding it. However I can't seem to find any stats on what I can do to the head/block. Everyone seems to just be swapping the motor/head. So if anyone out there knows how much I can machine off the head and how much I can bore out of the cylinders could they let me know. Please keep in mind that it's a street car and it needs to run on 91 gas. Thanks.