Both large date - no doubt here.
The inside loop of the 9 points below the bottom of the 7 on the large date, and points to the 7 on the small date.
The 9 has a 'hook' - sharply pointed inner curve on the small date, and a blunt squared point on the large date.
The 7 has a horizontal crease running across it on the large date - this crease is completely absent on small dates.
The top of the zero has a hump on the large date making the digit slightly egg-shaped. It is round on the small date.
The three middle letters of LIBERTY are very shallow and indistinct on most small dates, and rather sharply visible on most large dates.
And if that's not enough....
somewhere in the neighborhood of one in 25,000 coins you find in circulation that are dated 1970S will be a small date. Bet your socks that if you find two coins and the date characteristics listed above are the same on both coins you have two large dates. Save them and use them to compare future examples.
It took me over 20 years to find my first 1970S small date in circulation.