Originally posted by DanM
Can't even begin to think of it all. 
First of all, the bolt patterns are nothing alike, so you'd either have to drill new holes in the block or head, weld up the old ones, etc. Second, the bore is completely different, so I don't even know if the head would line up correctly PERIOD (may be too long, bigger bore on the head). If by some miracle it did line up, you'd have to weld up the chambers to match the block (unless you can bore the block out 6mm, which I doubt)...hell I dunno. It would be a very big mess. Just leave it at that. 
What USDM engine would be a bolt in for a 99 Civic Ex?