1726.75 was the previous high on ES on 19/09/2013
SPX was 1729.86 around the same time.
As it stands I would say that it can overshoot and SPX should print that 173x.x print.
However as we are close I am thinking I may want to build shorts.
Very tough call as this is TREND UP in QE mode and soon we shall have XMAS rally pollux.
Plan your trade, trade your plan!