I am not familiar with an aluminium alloy designation CC601. LM25 is a British designation from the standard BS 1490. It has been superceded by a variety of EN standards (BS EN 1559, 1706, etc.):
A356 is a U.S. designation. The Aluminum Association maintains the official chemical composition requirements, which are subsequently included in various standards: ASTM B 179, B 26, etc. You can find additional information from the following websites: