suppose 질문하겠습니다

gentlemen, suppose all the property you were worth was in gold and this you had placed in the hands of one man to carry across the niagara river on a rope.suppose 의that절이 were가 아닌 was여도 그냥 가정법 과거로 치나요?
아니면 suppose자체가 가정법 과거의 의미를 가지고 있어서 뒤에 꼭 were가 아니어도 되나요?이것이 궁금합니다.