There is a lot more to keeping both SPS corals and clams than just lighting. Water quality is just as important if not more so IMO. I think that this is firmly reinforced by the clams that are kept under anything less than MH. Clams as well as SPS need very stable water conditions, as well as high levels of calcium, and alkalinity.
To answer your question . . . yes you have enough light to keep clams, and sps corals. HOWEVER, this is only a fraction of the equation and not by anymeans the only or even the major factor.
What are your water levels like, and how long has your tank been up?
Justin