Maura Tierney and Courtney B. Vance have signed on to join the Broadway cast of “Lucky Guy,” the new Nora Ephron play toplined by Tom Hanks.Show reps the Main Stem debut of Tierney (“E.R.”), whose Off Broadway stage credits include the Wooster Group’s “North Atlantic” and Nicky Silver’s “Three Changes.” Vance hasn’t been on the Rialto since he appeared in the original Broadway cast of “Six Degrees of Separation” in 1990. Thesps join a cast that already includes Hanks, Christopher McDonald, Peter Scolari, Danny Mastrogiorgio, Richard Masur and Stephen Tyrone Williams, among others. The involvement of Hanks, also making his Broadway debut in the part, looks poised to attract big sales to the limited engagement, with the actor seeming a likely candidate (alongside fellow film names Denzel Washington and Julia Roberts) to prove himself a B.O. powerhouse. Show centers on late journo Mike McAlary, the tabloid writer whose storied career included Pulitzer-winning coverage of the Abner Louima police abuse scandal. Tierney will play McAlary’s wife Alice, while Vance is on board as the journalist’s editor. George C. Wolfe (“The Normal Heart,” “Angels in America”) directs. Show begins previews March 1 prior to an April 1 opening at the Broadhurst Theater.