I think the "new" valves are actually the ones that have been installed on E60 pumps since they came out. As with many parts on the pumps these valves will interchange with the "old" E47 pumps. I know that my local dealer only carries the larger ones.
You must replace the whole valve and coil assembly to switch over. The old coil will not work with the new valve.
I know this is an old post. But how do i tell if the C valve is the new style. I'm having a angleing right problem and bought a new valve and coil assembly. But put my old coil on because it checked ok for magnetism and power. Wonder if this could be my problem?