In a move sure to rankle the Arlington County Board, the county school board tonight is expected to adopt a $59.8 budget for the coming fiscal year, exceeding County Board spending guidelines by nearly $3.4 million.

The budget must receive final approval from the County Board, which is expected to receive the plan next week.

County Board member Walter Frankland, a vocal critic of school spending, said of the anitcipated action, "It's just a matter of whether they (cut) it now or later . . . "There's enough fat in that budget so that cuts can be made without endangering the quality of education in any way."

The County Board had urged the school system to limit county contributions to $43.5 million. But the budget plan, proposed in February by the then-superintendent Larry Cuban, asks the county for $46.9 million.

The school board is expected to make one change tonight in the salary and benefits package for school employes. The original budget proposal includes a 10 percent pay hike for employes, but the board is expected to juggle that figure tonight, allocating 9 percent for the wage increase and 1 percent to help offset skyrocketing premiums for employes' health insurance.

The change was recommended last week by board member Ann C. Broder, who has since picked up support from colleagues Evelyn Reid Syphax and Torill B. Floyd as well as groups representing employes.

Broder said her proposal, which would add $435,000 to the $1.34 million now budgeted for health insurance, would allow the board to increase its share of premium payments.

Marjorie McCreery, executive director of the Arlington Education Association, which represents most county teachers, said that even though teachers, are not pleased with the proposed pay hike, it is "more economic for employes to have the board contribute to help premiums" since that would leave workers with more spendable income.

Last week, in an effort to meet County Board spending guidelines, school board members considered plans to cut $2 million from the budget. Those cuts would have eliminated 33 positions and would have pared dowm, or eliminated, several programs.

The pland brought protests from nearly 350 angry parents, teachers and pupils at the board meeting last week.

The board later decided to make none of the cuts, and in a surprise move, Republican-appointed board member Syphax said she would move to adopt the budget intact. Board members Broder and Floyd, both Democrats said they would support her.

Claude M. Hilton, A GOP-appointed member who had requested a list of ways to trim the budget, said he plans to oppose Syphax's motion.

School board Chairman O.U. Johansen, who did not take a position last week, said later that he believes there is some fat in the proposed budget. But he added, "The (County Board) guidelines are not set sufficiently high to provide for the continuation of the kind of school program I believe the school constituency expects."