Carter administration officials will make "special efforts" to assure that a substantial number of blacks and Hispanics are hired when they pick 265,000 new, temporary federal workers to take the billion-dollar 1980 census.

New regulations in the Civil Service Reform Act will make it easier for the Commerce Department and its Census Bureau to let local managers pick neighborhood people to supervise census takers, and handle the 4-to-8-week jobs. Head counters will process forms and make visits to many of the nation's 68 million residences to determine how many people (and their race, sex and standard of living) live in the U.S.A.

Data collected by census takers is of vital political and financial importance. Congressional districts will be redrawn based on population shifts, and the distribution of $50 billion in federal funds to cities and states is largely determined by the numbers of poor, unemployed and minority group people found by census takers every 10 years.

After the last (1970) census, the Commerce Department estimated that it undercounted the nation's population by several million. Officials believed their temporary workers "missed" 1.9 percent of the white population, and 7.7 percent of the nation's blacks.

This year special efforts will be made to draw people from predominantly black and Hispanic neighborhoods who can win the trust and confidence of persons who might not answer the door, or might be afraid or unable to answer questions on the census questionnaire. This year, for the first time, the census questionnaire will be in both English and Spanish.

Black and Hispanic leaders claim that the 1970 undercount resulted in maintaining an unrepresentative status quo in the House of Representatives, which draws its districts along population lines. They think a better count would have resulted in more districts being won by black candidates, and would have given the poor and unemployed billions of dollars more in federal aid money.

White House officials have told census officials that this time they want the count made more accurately, and emphasized that one way to do it is to get more neighborhood blacks and Hispanics to participate both as enumerators and supervisors. Pay rates for the temporary employes have not been established, according to officials.

Census experts said that inflation, and new data required of the 1980 census will make it cost 4 to 5 times more than the $250 million of 10 years ago. They said 409 temporary census offices will be set up beginning Jan. 2. And they expect the 200 community-service representatives (70 have already been hired) will have to process 1.3 million job applications to get the 265,000 temporary employes who will take the census.

Past censuses have relied heavily on "housewives" to gather and process the data. But this year, as one official put it, "there seem to be fewer housewives . . . and the special emphasis will be on Hispancis and blacks to do much of the work. This isn't the sort of job anyone with a regular job can do since it will be 8 hours a day, and college students usually cannot fit it into their schedules."

Most of the 260,000 people who will be hired will be tested early next year, and put to work in March and April. Some jobs will last through the summer, and since 1980 will be a congressional election year, local and national politicians will be anxious at least to make it appear they have a hand in relieving unemployment, at least temporarily, for several hundred thousand potential voters.