Check this webpage.
http://www.the-answerman.com/sidlist/prl/index.asp He has an ongoing list of prls for Alltel. Included in these are prl's for data cards which enable EVDO on the smartphones on other networks. I travel a lot and I use the newest prl for the data cards and get Sprint's rev A in some areas that were 1x before updating to the data card prl. I haven't had any issues with Alltel because it is one of their prls. He has instructions on the page it install it. Hope this helps.
Jay