Look for a good showing by 69-year-old Jim Gunn of Alexandria in the Virginia State Golf Association Northern Section Senior Championship, at Belle Haven, July 13-14.

Gunn, a retired Army brigadier general who served in Vietnam and Korea, is chairman of the ages 55-and-over tournament. He can also play a little golf.

Gunn shot 3-under-par 32 on his opening nine holes en route to a first-round 72 at his home Army Navy Country Club course in the recent Northern Virginia Amateur. In 27 years as a member of the Arlington club, Gunn has won the club championship three times, the senior championship three times, and has helped the club to numerous team championships. In 1985, he won the Virginia State Seniors Championship.

Gunn can be seen practicing hours on end at the chipping and putting green, and said the short strokes are the most important shots in golf. "He lives up there, and he does have a short game," confirmed clubmate Gill FitzHugh.

Belle Haven head pro Wheeler Stewart, by virtue of an excellent showing in last year's national PGA Club Professional Championship, will play in the PGA Championship at Palm Beach Gardens, Fla., Aug. 6-9 . . . Scott Simpson, with his U.S. Open victory at San Francisco's Olympic Club, became the first member of the 1987 American Ryder Cup team. The complete 12-man team, which will play Europe's best at Muirfield Village in Dublin, Ohio, Sept. 25-27, will be announced at the conclusion of the PGA Championship. The winner of the PGA, the final Grand Slam event of the season, also qualifies automatically. Payne Stewart leads the Ryder Cup point race with 513.134, followed by Ben Crenshaw (374.800), Hal Sutton (350.300), Larry Mize (347.218), Kemper champion Tom Kite (297.219) and Dan Pohl (293.467) . . . Jane Mason of host Green Hill Yacht and Country Club near Salisbury, Md., successfully defended her title in the Women's Pepsi-Cola Invitational with 75-75 -- 150. Brenda Seymour of Hidden Creek, loser to eventual champion Lois Ledbetter in the Women's District Championship, was Pepsi runner-up with 76-81 -- 157 . . . Fred Widicus, two-time golf captain at Jefferson High in Annandale, and Tom Iredell, a three-time most valuable player at Good Counsel in Wheaton, have signed golf scholarships under Coach Clem King at the University of Virginia. Also signed to a team that lost only four players to graduation were Chris Geiger of Endwell, N.Y., Lee Porter of Summit, N.J., and Bernie Floriani of Dover, Del. Floriani played in the Bobby Bowers Memorial last year and likely will play in that tournament July 13-16 at Springfield . . . PGA Tour action can be seen a short drive southward at the Anheuser-Busch Classic at Kingsmill, in Williamsburg, July 9-12. Fuzzy Zoeller won last year with a final-round 64.

The Virginia Recreation and Parks Society is hosting a "Captain's Choice" tournament at Algonkian Regional Park in Sterling on July 31. The winning foursome will represent this area in the state playoffs at Kingsmill on Aug. 15. For more information, contact Richard Black at 938-8000 ext. 277 . . . The Northern Virginia Mid-Amateur is today, Saturday and Sunday at International. Neff McClary of Fairfax is defending champion.