As long as it is not a Continental (FWD 4.6) block it will be fine. I believe it is just in the casting webbing and the way the mounts are show the difference. Any 4.6 block will work. Or any 5.4 block if that is what you are going to run. I may be letting the LimeARita's do some of the talking tonight though.
Yeah, just remember the differences is that the only difference between the 4.6 heads and 5.4 heads is actually nothing. It's all in the block. The longer stroke of the 5.4 block gives it the extra displacement.