There' s nothing wrong with 75gr heads. I' ve used them for years now with good results. And a deer shot through the lungs does not know whether the hole is 1" or 2" . Dead is dead. Two I would recommend are the Wasp SSt and the Innerloc, with a slight edge to the Innerloc due to it' s almost indestructible nature.
Actually, you might even find that yu get better arrow flight. Sometimes, depending on setup, carbon arrows get along better with the lighter heads.