Virginia's old guard conservatives assembled at a rooftop restaurant here last week to bestow a final blessing on Wyatt B. Durrette, the 43-year-old Republican candidate for state attorney general.

It was a symbolic gathering, reverberating with the special sounds of Virginia money, power and history. For those who missed the implications, there was an effusive Mills E. Godwin, the former Democratic and Republican governor: "Wyatt Durrette has a basic philosophy . . . that the majority of the people of Virginia are in accord with, a political philosophy shared by most of us."

In other words, if Durrette is elected Tuesday, he will have little trouble winning support from Godwin and key conservative fund-raisers in a bid for governor in 1985. In fact, many of Virginia's old-line conservatives feel more comfortable backing Durrette than they do J. Marshall Coleman, this year's Republican gubernatorial nominee.

Durrette, a Northern Virginia lawyer and former Fairfax County legislator, was an early favorite in the attorney general's race. He has raised and spent more money and is better known statewide than his Democratic opponent, Gerald L. Baliles, a Richmond-area legislator and lawyer.

Yet despite his powerful supporters, polls have yet to show Durrette with a comfortable lead. He and Baliles have been neck-and-neck, and although one recent poll showed Durrette ahead by a slight margin, close to half the voters polled were still undecided.

Both men are predicting victory. For Baliles, the optimism comes largely from the perceived strength of the Democratic ticket, shown by polls giving Democrat Charles S. Robb an early lead in the governor's race, and controversy over conflict-of-interest allegations regarding Nathan Miller, the Republican nominee for lieutenant governor. At campaign appearances, Baliles plugs the Democrats as "a stable, experienced ticket, free from any questions."

And Democrats, who once viewed Baliles as an underdog, have been encouraged that Durrette, who had raised $438,907 as of Oct. 23, has not used his money to swamp the airwaves and highways with ads. So far, Baliles has actually outspent Durrette on TV and radio, although Durrette is the only one of the two to broadcast ads in the expensive Washington television market.

Baliles, who reported $287,000 in contributions since the start of the general election campaign and about $420,000 in the last year, has run a more frugal campaign, said Democratic financial codirector Curry Roberts. "We spent $102,000 getting the nomination and Wyatt didn't have a fight for his. How he has used his money perplexes us," said Roberts. He said Durrette outspent Baliles on hotels and other nonessentials. Another Democrat dubbed Durrette a "caviar candidate."

Baliles' campaign style fits his cautious and meticulous personality. A man who admits he is not one for self-analysis, Baliles, 51, is known for approaching problems, votes and campaigns with sober determination. He said he has an "almost scholarly" interest in government, which led first to a job in the attorney general's office and in 1976, to the House of Delegates.

Baliles stresses his experience as an assistant and later, deputy attorney general, and his record as one of the most effective Virginia legislators. He is a moderate-to-conservative on the issues, although the issues have not played much of a role in the race.

Durrette, who returned to the political stage this year after a four-year absence, had a reputation as an able legislator during his six years in the House of Delegates. The more forceful speaker of the two, Durrette was a top athlete and president of his class at Virginia Military Institute and Washington and Lee University.

Stumping in Northern Virginia, Durrette dwells on his ties to the area and ticks off a family genealogy that, he said, establishes his truly Virginian pedigree.

Unlike the candidates in the two other statewide races, Durrette and Baliles have remained on friendly, respectful terms. But within those bounds, Baliles has repeatedly questioned whether Durrette has always been conservative.

By hitting at Durrette's one-time support for "meet and confer" legislation for public employes, Baliles has raised an issue used effectively by Coleman in 1977, when he defeated the then-favored Durrette in the contest for the Republican attorney general nomination.

Colleagues who served with Durrette in the General Assembly between 1972 and 1977 praise his ability but also remember a shift in his positions after 1975 -- when he had already set his sights on higher office.

"He did become more conservative as he served in the General Assembly," said Del. James Dillard (R-Fairfax), "but I think his positions changed with the climate of Virginia. I think he became more conscious of statewide issues but he wasn't hanging out on a limb because of that."

To Del. Dorothy McDiarmid (D-Fairfax), Durrette's most memorable switch came on the Equal Rights Amendment. "He originally backed the ERA, but when he started working for Reagan in 1976 he said he changed his opinion," she said. "I was sort of surprised."

Durrette has said that on ERA and "meet and confer" legislation, he found through research that his original positions were wrong. But he staunchly defends the depth of his conservative convictions, noting that he headed a Youth for Goldwater chapter during his graduate-student days in Maryland.

His arguments have clearly prevailed with Virginia's leading conservatives. In fact, at the Richmond luncheon, Godwin praised Durrette for his "quality of predictability" and as a candidate with whom Virginians can "feel comfortable."

But despite the endorsements and the ads, the attorney general's race has gone almost unnoticed by most voters. "In the third race, I don't care if it's God running against Superman. Until you get down to the wire, the public perception isn't there," said state GOP spokesman Neil Cotiaux. "That's the nature of the third race."