<p>Stanford: requires both all SAT and all ACT scores, so send both</p>
<p>Yale: requires either all ACT scores or alternatively all SAT and SAT II scores. Don’t know your SAT II scores but if you intend to send any SAT IIs you must also provide all your SAT scores. Moreover, if you send just ACT and SAT II scores, Yale will use only the ACT
score for admission because SAT IIs are considered only with the SAT. Thus if you have good SAT II scores to send you should send both the SAT and ACT; if you have lousy SAT II scorers consider sending only the ACT; and if you have no SAT II scores then send only ACT.</p>
<p>Harvard and Princeton: you can send those scores you want to send and withhold others but likely you should send both. ACT is probably better but they follow, as other colleges do, the rule that if you send both SAT and ACT they will use that one they believe is the higher to determine admission and thus let them make the choice.</p>