The Virginia General Assembly, after a full day of rancorous rhetoric and a 90-minute filibuster, bowed to the wishes of the Justice Department tonight and passed a revised redistricting plan that the Reagan administration says will give blacks more clout in state legislative elections.

The plan, which is expected to win quick approval from Justice, still must survive eight lawsuits, which charge that the proposal still dilutes black voter strength and violates Constitutional requirements for equal representation. Those suits will be heard by a U.S. court here Thursday.

The legislature's ratification of the compromise redistricting plan, worked out in Washington last week after the original plan was held to violate the Voting Rights Act, was expected to be pro forma. Then Del. William D. O'Bryan, a Democrat from Hanover County, rose on the House floor with his home telephone book in hand.

"The following people will not be represented in the halls of this chamber next year," said O'Bryan as he began reading the names and addresses of some of his 50,000 constituents.

O'Bryan, a tall, paunchy legislator, proceeded to argue constitutional issues, appealed to a sense of fair play and even invoked the memory of Patrick Henry in an attempt to keep his county from being merged with another suburban Richmond county three times its size. O'Bryan had made it to the "M's" when his colleagues, citing House rules drafted by Thomas Jefferson, forced him to abandon his telephone book.

Jefferson's rules, House Speaker A.L. Philpott said, prohibit any legislator from "abusing" the House's time by reading printed material. Philpott directed O'Bryan to cease reading and the legislator was able to last only 20 minutes more.

Once he was silenced, the 100-member House quickly approved the Justice-endorsed plan with only 12 dissenting votes. It was sent to the state senate where it passed by a 24-to-9 vote.

O'Bryan's ploy to delay the plan was only the latest episode of what some call the Virginia Redistricting Show, a long-running series of lawsuits, political pratfalls and federal interventions that were prompted by the 1980 Census and the legislature's mandate to reapportion itself before the scheduled Sept. 8 House primaries. The General Assembly set the stage for the drama this spring when it passed controversial plans to carve up both the Senate and House districts to reflect population changes. Since then, the battle has been joined by civil rights groups, city and county boards, and civil liberties groups.

Both the Senate and House plans were vetoed within the last month by Justice Department officials who held they discriminated against black voters in the state, a violation of the Voting Rights Act.

Justice officials, mindful of Virginia's election timetable, worked out a compromise last week with the House and promised that if it could be ratified by the full General Assembly, Justice would have it approved in advance of the federal court session Thursday.

"I can tell you with all the confidence I have in my command (that) if this plan is passed, it will be approved by the Justice Department," said Del. Claude Anderson (D-Buckingham) who told his colleagues that Justice officials had been sent a preliminary copy of the plan.

Still, it was apparent from the outset of a House elections committee hearing this morning that many groups remain unhappy over the plan.

Jack Gravely, Virginia director of the NAACP said "what happened in Washington last week was (an attempt) to give them a little to keep them quiet . . . But we haven't been given enough."

The most vocal opposition to the new plan came from representatives of small or rural areas who objected to being placed in districts with large or suburban localities.

"Henrico County will overwhelm any candidate in Hanover," complained Del. Lewis Fickett, a Democrat from Fredericksburg which had shared a district under the old plan with Hanover. Fickett ended his presentation with an appeal for justice.

"Justice is in short supply today," whispered Arlington Del. Mary Marshall to one of her colleagues on the committee.

Dick Gillis, the mayor of the town of Ashland in Hanover County, told the committee that mixing Hanover's 50,000 residents with Henrico's population of 180,000 would be like "dropping one Alka Seltzer tablet into a 180,000 gallon water tank. One sip would do nothing for an upset stomach."

Switching metaphors, Gillis compared Hanover to Jonah and said: "Maybe 10 years from now we will be belched out of the belly of the Henrico whale."

The committee rejected the appeal for a single member Hanover district by an 11-to-9 vote.

Judy Goldberg, a lobbyist with the American Civil Liberties Union of Virginia called the compromise plan "an intentional act of racial discrimination." She blamed multimember legislative districts for giving blacks only four of the House's 100 seat although blacks account for 18.6 percent of the state's population. A single-member redistricting plan drawn up by the ACLU was defeated 18 to 2 by the elections committee.

After the redistricting plan finally was passed, House leaders expressed confidence that the federal court will approve it. But Del. Bernard Cohen (D-Alexandria) was more pessimistic.

"The plan is not going to pass the court, it is obviously unconstitutional," said Cohen. "I don't see how we're going to have elections in the fall . . . the General Assembly is marching like lemmings to the sea of disaster."