Can 1 Day 1 Park tickets be converted to 1 day 2 park tickets at the gate?

[hulabird]

I am thinking about cashing my Hilton HHonors points out to get some Universal passes. I want to get an adult 1 day ticket, but it is for one park only. Can this be converted to a 1 day 2 park pass when I get there? would just pay the difference.

Any help would be appreciated.

 

[hulabird]

bump