In the capital's newest year-round industry, football, the Redskins offer three new names today and the Federals twice as many, including two old/new ones to kick around: Dale Castro and Jim Corcoran.

Free agents signed by the NFL champions: receivers Ray Arnold, 6-foot-1 out of Cal State-Hayward and a New England NFL trial, and Mark McGrath, a six-game, four-catch veteran of the Seattle Seahawks at a Smurfish 5-11; and Van Heflin, a 1982 Cleveland Browns draftee/cut who played quarterback and running back, well, at Vanderbilt but at 6-2, 230, now is a tight end.

In for USFL tryouts: Jeff Sevy and Robert Newton, Chicago Bears offensive line vets; Phil Murphy, a full-fledged L.A. Ram on defense in 1980-81 now an offensive tackle let go by L.A. Express; Tony Samuels, a 1977-80 Kansas City Chief at tight end; plus Maryland's Castro and Georgetown's Corcoran, who were among the Federals' earliest signees but were cut in Florida. Now both will contest Dana Moore, Washington's short-time punter/kicker.

Coach Ray Jauch ventures that recuperating tailback Craig James and quarterback Mike Hohensee could both "be dressed" for Monday's RFK date with the Arizona Wranglers. But did Joe Gilliam's presence (as one of just two players) at the Federals' press lunch yesterday portend that Monday night's fireworks might include the ex-Steeler's D.C. debut at quarterback?

Jauch hedged.

Gilliam was "dressed" for the last two games, as the 41st man on a 40-player active roster, under a USFL rule providing for emergency activation in case of depletion at a position. Now, it could come down to Hohensee's health--and the practice performance, at which Jauch says Gilliam has "made excellent progress"--of Hohensee, Gilliam and Chris Garrity (last week's active No. 2) as to who looks over Kim McQuilken's shoulder. With Jauch saying, "Kim has done an admirable job, but you have to look at getting the ball into the end zone, which we haven't been . . ."