All transparency film is metered for the highlights. You might want to try graduated neutral density filters to knock down the sky so the shadows don't block up.
Thanks Pinholemaster for your reply. I will shoot it like a any other colior slide film then. You made a good tip for the Graduated ND filter and sky, I never thought of that. The bummer is I already had it loaded in an M3 with 5 shots. Maybe next roll I will load it in my Nikon F3.
Consider the ultimate use of the transparancies. If they are projected in fairly high ambient light, they should receive more in-camera exposure. If you have the luxury of projecting them in a very dark room, less exposure is better. Long ago somewhat dark transparancies seemed to be preferred for reproduction. Do avoid blocking highlights.