you're going to need to split them open to expose the meat. like any fish, you're gonna be grilling this quickly. a minute or two too long, and they'll get tough and stringy.
and baste with butter before you put them on the grill to help keep them moist.
silversage had a good technique of the way she split and cooked them, they came out beautifully with the meat popping out of the shell. i'll see if i can find her post.