Well, generally yes. But, 160 is the upper end that sacchrification happens at (turning starch into sugar). If you strayed a degree or two high, you would denature the enzymes that convert the starch to sugars and be simply steeping. 152-158 is the most common range for mashing, although there are reasons to do rests at lower temps that that.
That said, according to Brewers Friend, your ingredients would produce the following beer(assuming 65% efficiency on the mash):
And that does conform with the BJCP definition of an American Stout.