Richard A. Viguerie, the conservative direct-mail fund-raising wizard, said yesterday he is "seriously considering" seeking the Republican nomination for lieutenant governor of Virginia in 1985, an action that party officials said could alter the dynamics of all statewide races.

"I've talked to a fair number of people. I'm seriously considering it," said Viguerie, who is regarded as one of best-known members of the conservative New Right.

While Viguerie, 51, is well known in national politics, he has never run for public office and has not been active in Virginia politics. His direct-mail firm, based in Falls Church, has mailed out about 110 million fund-raising letters this year and raised millions for conservative candidates and causes.

"I have a feeling that my life is pointing in that direction running for public office ," Viguerie said in an interview. "I've been quoted as an outspoken critic of a lot of people in the political arena. It's easy to stand on the sidelines and criticize. Now I feel maybe I should get in there and make some contributions."

Viguerie, publisher of the Conservative Digest, said he will make a decision within the week.

J. Marshall Coleman of McLean, who announced Monday that he was running for the number two spot instead of governor, is the only Republican in the race. He declined to comment on how a Viguerie candidacy would affect his race.

Some Republicans say his candidacy could throw the party into disarray. "It's a real wild card in the gubernatorial race," said Fairfax County Supervisor Thomas M. Davis, who is supporting the gubernatorial campaign of Republican Wyatt B. Durrette.

Virginia's statewide candidates are selected by a series of mass meetings and a nominating convention, instead of by a primary. Some Republicans said that Viguerie could bring to the meetings supporters who have not been active in state politics, and thus will have no ties to Durrette, a Richmond lawyer, or Rep. Stan Parris of Fairfax, the other gubernatorial candidate.

"It could put him Viguerie in a position to be a power broker" at the convention, said Davis.

Viguerie said he ruled out the governor's race because "Stan Parris and Wyatt Durrette have been out there working the vineyards for many years, and they have strong allegiances with a lot of the conservatives. Most of the people I've talked to are really undecided between Wyatt and Stan."

He added, "The lieutenant governor is more doable at this time."

Davis said the lieutenant governor's is "a safe race for the Republicans this year" because state Sen. L. Douglas Wilder of Richmond, the only Democrat to announce for the office, "is so liberal that he is not in tune with mainstream Virginia."

Republicans said it was hard to predict how Viguerie would do in the Republican race because Viguerie has statewide name recognition and proven fund-raising abilities, but has little base within the state Republican Party.

"I don't know if he's ever been to a Republican convention in Virginia or a mass meeting in Virginia, yet he wants to become a deputy choirmaster without having yet to join the church," said Richard Cullen, a Richmond lawyer and close associate of former governor John N. Dalton. "I think he'll have a tough row to hoe."