If all you have is the block with no internals,it is hardly a illegal engine.If your going to rebiuld it then use current smog equipment to put it in,I see no issue.And as long as you use carb certified mods there shouldn't be a issue there either.Another thing is,what car are you putting it in?If your putting it in a 86 crx then it would be legal because it is a newer motor,and the manufacturers smog equipment was better.