Your coin looks to be a small date variety. It has a point at the top end of the Nine, and the weak liberty. The Large date has a 9 with a blunt top end inside of curve. Compare with this site. And search for other post. http://www.lincolncentresource.com/smalldates/1970Ssmalldate.html
There is a curl on the 9, the 7 is high and Liberty is weak. But these are all borderline markers on this coin.