Send both. Admissions will choose the score that gives you the most WCS points. Highly unlikely that the SAT score will produce more points, but since both scores are excellent, there is no downside.
According to the ACT/SAT Concordance on act.org, a 36 ACT converts to a 1590 SAT with a range of 1570 - 1600. It would appear that a 36 ACT would be better, but since it is unknown exactly how the WCS score is calculated, you insure against any unknown quirks in the system by submitting both scores.