Need Help With 1968-D LMC.

They all looked that way that year. It was an issue with a swelling master hub. So the swelling passed on down through the whole chain:

In 1969 they made a new Master Hub and fixed the issue:

Note how the design was enlarged by comparing the bust on each coin. Thus when we see this enlargement on the coins, they are often called large and small dates when they realize this happening in the middle of the year. Note how much smaller the bust is on the 1969 and the distance between the devices and the rims.