Virginia Gov.-elect Gerald L. Baliles and his Republican opponent, Wyatt B. Durrette, spent nearly $8 million on their campaigns, well above earlier estimates and more than has ever been spent in a single political race in the state, according to reports made public today.

Democrat Baliles outspent Durrette by about $300,000, $4.1 million to $3.8 million, and ended up owing about $80,000. Durrette ended the campaign with debts totaling $157,865, and loans of $446,221, according to financial statements prepared for the State Board of Elections.

When the race began there were estimates that each candidate would spend $3 million, a figure that was soon erased by the heavy purchases of television time by both campaigns. The previous record for a Virginia race was the $5 million spent in the 1981 race for governor won by Democrat Charles S. Robb.

Baliles, a former state attorney general who will replace Robb Jan. 11, raised $515,075 since Oct. 29, and much of that came, as it often does to winning candidates, after the votes had been counted on Nov. 5.

Reports were available today from only one of the other winning Democrats in last month's election, State Del. Mary Sue Terry, who will become state attorney general.

Terry, who led the ticket with 61 percent of the vote, spent $1.3 million, the most ever for a candidate for the state's top legal office. The reports of Lt. Gov.-elect L. Douglas Wilder of Richmond were not available.

In the final days of their campaigns, both candidates for governor were spending money as fast as it came in -- and in some instances, faster.

Baliles aide Chris Bridge said the campaign went into debt at the last minute with the purchase of $100,000 in television time.

Baliles appeared to have directed a greater percentage of his spending, nearly half, for television commercials than did Durrette. While some of Durrette's critics cited his failure to spend similarly on television as contributing to his defeat, the final report showed Durrette, a Richmond lawyer, poured nearly $150,000 into TV commercials in the final week.

The biggest contributor in the campaign was Virginia Beach developer R.G. Moore, whose benevolence was bipartisan, although tilted toward the winners. His company gave $250,500 to Baliles, including $50,000 on Nov. 14. In the closing days of the campaign, he also gave $10,000 to Terry.

Earlier, Moore gave $100,000 to Durrette, $10,000 to Terry's Republican opponent, Del. W.R. (Buster) O'Brien of Virginia Beach, and $150,000 to Lt. Gov. Richard J. Davis, who lost the Democratic nomination for governor to Baliles.

Durrette, a former Fairfax County legislator, attempted to keep pace as election day neared by borrowing $100,000 from three Richmond sources -- $50,000 from the family of Bruce G. Gottwalds, an Ethyl Corp. executive, and $25,000 each from financier Lawrence Lewis and contractor William H. White Jr.

Durrette's financial report showed all three loans had been forgiven. Stan Maupin, Durrette's finance manager, said the loans were made with the understanding that they would be repaid only if Durrette won.

O'Brien, a lawyer, raised $734,960 and spent $938,460, compared with Terry's $1.3 million. About $600,000 of Terry's expenses were for television commercials.

The losing Republican candidate for lieutenant governor, State Sen. John C. Chichester of Stafford County, fared better on the balance sheet than his running mates, thanks in part to a $70,000 loan he made to himself. He wound up about $45,000 in debt, reporting contributions of $905,115, expenses of $881,699, debts of $106,201 and a balance on hand of $37,710.

Wilder's financial report neither had been received by the elections board today nor was made available by his office. The deadline for mailing the report was 5 p.m. Thursday.

Wilder's campaign manager, Paul Goldman, announced earlier this week that Wilder was setting up an Underdog Fund, partly with money left over from his race. An aide to Wilder said today that the campaign ended up with $76,720 in cash.