President Ford's budget for the housekeeping and personnel costs of government calls for an average 28 per cent pay raise next month for top elected and appointed officials; anticipates a 6.5 per cent salary increase in October for civil servants and military personnel, and requests 6,500 new full-time jobs over the next fiscal year.

Overall federal employment in government - both full-time and part-time - would remain at the 2.8 million level if Congress approves the Ford budget.

The first item Congress will tackle is the tricky issue of top government pay raises.

The Ford executive-legislative-judicial salary plan, which President-elect Carter has endorsed, goes into effect automatically within 30 days unless either the Senate or the House vetoes raises for elected or appointed officials ranging from the Vice President on down to the lowest level subcabinet job. Most persons who would benefit from it will be appointees of the Carter administration.

If the pay package should become law, it would also trigger pay increases for 20,000 career federal executives - most of them in the Washington area - ranging from $29 to $7,900 a year. (Details in the Federal Diary on Page C2).

It will be up to President Carter to decide later this summer the exact amount of the regular Oct. 1 raise for federal white-collar civilians and military personnel Ford, besides estimating the increase at about 6.5 per cent, projected another 6.25 per cent increase for October, 1978.

There would be 12,900 new government jobs, but nearly half would be part-time or summer positions. The 6,500 new full-time jobs would go to Veterans Administration, Tennessee Valley Authority, Agriculture, Health, Education and Welfare, Housing and Urban Developemnt, General Services Administration, Interior, Commerce, Transportation and Treasury.

The Defense Department would drop 4,200 jobs to 977,100 by September, 1978. The Federal Energy Administration would lose 200 positions (to 3,700 jobs). The Energy Research and Development Administration would add 500 jobs, to 10,000 employment.

President Ford based his top pay proposals on recommendations made last month by a blue ribbon citizens panel. It proposed substantial increases - from 20 to 40 per cent - for key elected and appointed officials. The citizens group, appointed by the three branches of government and headed by former Commerce Secretary Peter G. Peterson, said many of the officials have had only one 5 per cent pay raise in six years at a time when inflation boosted prices 60 per cent and average private industry pay was up 70 per cent.

Under the Ford proposal, Vice President-elect Walter F. Mondale would get $75,000 a year, a raise of $10,000. Cabinet officers would go up $3,000, to $66,000; assistant secretaries and others in Level II would go up $12,900, to $57,500; Executive Level III appointees would go up $10,500, to $52,500 and Level IV of the executive pay schedule would rise $10,000, to $50,000 a year. Level V, which is linked the maximum civil service salary at Grade 18, would go up to $47,500.

The Chief Justice would get a $9,400 raise, to $75,000; associate justices would go up to $72,000 and judges on the courts of claims, military appeals, customs and patent and district courts, customs court and the tax court would go up $12,500, to $54,500.

Members of Congress who now get $44,600 would go to $57,600 a year. Ford agreed with the Peterson group, which made the pay raise proposals for members of Congress contingent on adoption - or the intention to adopt - a strict new conflict-of-interest code. It would bar most outside earnings, legal fees and salaries for service on boards or corporations that many Senate and House members now draw.

But the political realities of the situation are such that it is unlikely Congress can, or will, adopt the controversial code before the raises are due to go into effect. Both Republican and Democratic congressional leaders have subscribed to the idea of a code of conduct for members.