The site plan with elevations is posted to AULCC. It is such a bad copy that I can't read the height. But it's taller than I thought at 45 floors. There is a 46 floor for mechanical.
ftp://ftp.ci.austin.tx.us/ATD_AULCC/...ts_PLAN_01.pdf
EDIT: The height is listed elsewhere in the site plan as 504'.