On a 216 there is a tin lifter cover that goes all the way up to the valve cover, There are holes in it for the spark plugs. In a 235 the lifter cover just covers the lifters. The spark plug side of the head is not covered with a tin piece.
So considering the nuts on the top of the valve cover and the tin lifter cover that doesn't cover the spark plugs, this is probably an early 235?