The General Services Administration, which would like to be known as the government's business manager instead of just its landlord, would become a bigger revenue-producing agency under President Reagan's proposed fiscal 1984 budget. The agency would spend $649 million, or about $6 million less than this year, but would be expected to produce $961 million, or more than $300 more than the current fiscal year.

The sale of surplus commodities from the National Defense Stockpile is expected to raise $314 million, up from $197 million this year. But the administration has cut the agency's targets for its land sales program from a projected $2 billion in fiscal 1984 to $647 million.

GSA officials have been working to cut expenditures for furniture, travel and supplies. This year the GSA budget includes only $7,000 for new furnishings, down from $1.8 million four years ago.

Spending for fire-safety measures in federal buildings would drop by 37 percent, from $27.95 million to $17.4 million, as a six-year effort to improve safety standards draws to a close. Spending for environmental protection measures, such as removing asbestos from federal buildings, would drop by more than 65 percent.

As the government's builder, the GSA wants to start building a $67.5 million headquarters in Portland, Ore., for the Bonneville Power Administration and a $15 million building in Knoxville. It wants to do $200 million worth of work on other federal buildings.

The GSA also is trying to cut long-term leasing costs by buying buildings instead. This year's budget includes $20 million for the first purchase, a building in Dallas. Although the number of federal employes is expected to decline further next year, the government's rental bill is expected to hit $880.5 million, about a 10 percent increase.

However, the government's utility costs are expected to increase less than projected last year because of milder winters and lower inflation rates, according to Raymond A. Fontaine, assistant administrator for financial management.