I have found that the front crossmember difference is not a year thing, but more where the car/frame was manufactured. Some have the tie down point right under the engine, some don't. I have seen 65 and 66 cars both with and without the tie-down on them. I parted out a '66 4dr HT that had the tie down, and parted out a '66 2dr. HT that didn't have it. 2dr and 4 dr frames were the same.