[Tex/LaTex] Using ACM style produces wrong page size

acm

I'm using the ACM "Tighter Alternate style" to write a document. The submission instructions state that I have to create a PDF in US letter format but unfortunately, my PDF is A4. How can I change this to US letter?

I have tried the geometry package (\usepackage[letterpaper]{geometry}), but this produces 6 instead of 4 pages and I can read everywhere, that there are only slight differences between both sizes… Additionally, I looked into the config.ps as described here, but proposed lines to change exist both in my config.ps.

Best Answer

It is an officially (I asked ACM support) accepted way to do this

\pdfpagewidth=8.5in
\pdfpageheight=11in