The engine is not supposed to be level but if the carb base is pretty level then it's OK. The rubber pads deteriorate in time and it's possible that the spacers weren't correct before. This applies to the timing cover mounts and not the later side mounts. Could you have placed the little metal cup that the rubber fits into upside down? Just wondering.
Tim will be along and offer up his one his illustrations before long and that will explain it all.
