Trying to format a zine

[yaque-0000]

I want to format a zine, 16 pages 4.25x2.75 (1/8 of letter sized paper per page) 

It would be 16 pages double sided on one sheet of letter paper. I figured out the page size but I can't get multiple pages on one sheet. When I go into "print booklet" it has the spread on the top left corner with 8 sheets of paper. I need each 16 pages, 1 sheet of paper double sided.

I hope this makes sense.