Okidata Microline 320 turbo printing PDF question.

Alright kind of an odd question, but my work is pretty much riding on it.

Car dealerships use the okidata microline 320 turbo, and as such I need to make sure my PDF's can print well on this model. I can manage printing any form 11" x 8.5" or smaller, however when I go above this, say 24 x 8.5 or somthing for a financing form, it wont let the page get bigger, I fiddled with the options and just cant seem to get it to print a full sized long form. Any ideas?