A picture caption in yesterday's Washington Post should have said that Arthur F. Burns is President Reagan's choice for ambassador of West Germany, not Britain.

House Republican leaders and their conservative Democratic alliees yesterday said they are prepared to introduce an across-the-board substitute for Democratic-drafted budget cuts if the cuts fall too short of President Reagan's goals.

The alternative may exclude such controversial Democratic proposals as closing up to 10,000 post offices and ending federal impact aid, while bidding for support of wavering Northeast-Midwest Republicans with less drastic cutbacks in the college loan program and more fuel assistance for the poor.

It would almost certainly include a modified version of the block grants Reagan wants in order to transfer control over nearly 100 federal programs to the states, an idea that was mostly rejected by House committees in devising their budget cuts.

House Minority Leader Robert H. Michel (R-Ill.) confirmed the standby budget strategy just as most congressional committees finished their budget surgery a day ahead of today's deadline for proposing program cutbacks totaling more than $35 billion in savings for next year.

It appeared that most committees in both houses would meet or come close to their quotas for cuts, at least on paper.

But both White House and House Republican leaders were compiling lists of what Michel calls "phony cuts and bookkeeping chicanery" by which committees may be claiming savings that aren't really savings at all.

There were also complaints of Reagan policy initiatives that were ignored and of failure to make prescribed savings for 1983 and 1984 as well as 1982, as Congress required in its budget resolution last month.

While no decision has been made to push for the substitute, Michel said, "You can't take chances. . . . You have to be absolutely sure you have an alternative that is agreeable to the administration."

Michel said Republicans will be working over the weekend, if necessary, to put the finishing touches on the substitute so it can be dropped in the hopper if Republican leaders, the White House and their conservative Democratic supporters decide to go with it.

The budget committees of both houses are to meet early next week to compile the committee proposals into an amnibus "reconciliation" bill for approval of the two houses.

On the House side, the Rules Committee then will have to decide how many, if any, amendments to allow when the bill comes to the floor. That could be crucial for both the Republicans and the liberal Democrats who want amendments to restore some of the money that is being cut.

Democratic leaders reportedly were split yesterday over strategy on amendments.

Some, like Budget Committee Chairman James R. Jones (D-Okla.), want no amendments, on the theory that they could unravel the package. Others, like Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) and some committee chairmen, want amendments so that the House as a whole can reject some of the cuts. The problem is that it would be awkward, or worse, to allow liberal Democrats to offer amendments and deny similar courtesy to Republicans and conservative Democrats.

Moreover, Michel indicated that the Republicans may try to reverse the Rules Committee on the House floor if the committee denies a vote on a GOP substitute. "We're getting down to the point where we may have to play hardball," Michel said.

The Democrats were clearly concerned. "They [the Republicans] want to overturn the judgment of all the committees of the House," complained Majority Leader James C. Wright Jr. (D-Tex.). "I have never seen such unmitigated arrogance."

But the Republicans, too, were concerned that they might not be able to muster the extraordinary support from both parties that enabled them, despite Democratic control of the House, to win the first phase of the budget battle last month.

In that maneuver, they succeeded in junking a Democratic budget blueprint in favor of a modified version of Reagan's budget, drafted by Reps. Phil Gramm (D-Tex.) and Delbert L. Latta (R-Ohio), that set out program-cut quotas for the committees.

"Son of Gramm-Latta," as some have dubbed the latest Republican initiative, may be more difficult to sell.

As many as 15 Northeast-Midwest Republicans are threatening to split with their party on the cuts if some money is not restored for energy, education, Medicaid and transportation. Moreover, some members are said to be reluctant to reject the work of their legislative committees, especially if they achieve their quota of cuts. "I suppose it would be harder this time," Michel conceded.

But the White House is hardly napping. Budget director David A. Stockman has been meeting so often with House Republicans on committee-monitoring and contingency-planning that James B. Hedlund, minority staff director of the Budget Committee, said, "We know every tie in his wardrobe."

And the Office of Management and Budget has set up an elaborate system of hotlines, desk officers and daily reports for handling tips on problems from Congress.

Moreover, OMB officials also have compiled lists of wayward behavior that includes counting savings for post-office closings that could subsequently be vetoed by Congress, making cuts from an energy authorization that has never been adopted and "capping" food-stamp funds in such a way that a supplemental appropriation will probably be needed later.

They also point to deep cuts in salaries and expenses for several federal departments. For instance, Treasury would have to close its Bureau of Government Financial Operations or be left with only enough money for postage to send out government checks for five months next year, officials said.

Meanwhile, as the House committees wrapped up their work, the House Commerce Committee couldn't round up a majority for Democratic-proposed cuts, so Chairman John D. Dingell (D-Mich.) simply shipped the Democratic plan off to the Budget Committee over his own signature.

This did not appear to comply with rules of the budget game, but Budget Committee staffers said a solution probably could be worked out.