Arlington Republicans voted yesterday to endorse County Board member Walter L. Frankland Jr. and School Board member Michael E. Brunner to run as independents for the two County Board seats up this fall.

A record 1,602 persons waited in line up to an hour to vote for candidates running as independents for the County Board, commonwealth's attorney, sheriff and treasurer. The six-hour GOP canvass was held at the Lyon Village Community Center.

As independents, the candidates hope to capitalize on the large number of Arlington residents who are federal employes and barred by the Hatch Act from working for party nominees.

In the County Board race, Brunner, a U.S. Agriculture Department executive, got 1,054 votes to the 1,016 cast for Frankland, a two-term incumbent who is executive vice president of the Silver Users Association. John Marshall, a U.S. Education Department manager, got 621 votes.

They are expected to face Democrats Richard A. Buffum and Albert C. Eisenberg in the November election, which will be critical to Republicans because Democrats now control three of the five board seats.

"We've got to hit 'em and nip this thing in the bud," said Frankland, referring to the victories of Democratic endorsees or nominees in the last three County Board elections. "We've got to win these two seats this year and then next year get our majority back."

Because none of the three candidates for sheriff won a majority of the endorsement votes cast, there will be a runoff next Tuesday among the top two vote-getters, John Baber and Charles Bonneville. Baber polled 676 votes to Bonneville's 565. David Ryan, who also sought the endorsement for sheriff, received 312 votes. The runoff will be from 5 p.m. to 8 p.m. next Tuesday at the Lyon Village Community Center.

In the treasurer's contest, County Board member Dorothy T. Grotos, who decided against seeking a third board term, got a standing ovation and 1,201 votes to the 341 cast for her opponent, William Nehrke.

Commonwwealth's Attorney Henry E. Hudson, who was unopposed in his bid for endorsement for reelection, was the top vote-getter among all the candidates, getting 1,383 votes.

The large turnout delighted party officials, who said they hoped it was an indicator of better times at the polls this November, but speculated that many of the newcomers were Democrats who came out to support individual candidates. The balloting was open to any registered voter who would sign a pledge to support candidates endorsed by the Republicans.