SOME VERY STRANGE and turbulent maneuverings seem to be going on backstage as the administration gets ready to present the President's new welfare program. In fact, as the August deadline Mr. Carter set approaches, we are put in mind of nothing so much as that charmed moment right before the school play begins. You know the moment we mean: audience seated and beaming expectantly toward a still-closed curtain which occasionally bulges out monstrously in an improbable place or two, and from behind which there is to be heared the lamentable din of tramping, whispering, shushing, shrieking, fighting - and at least one calamitous-sounding crash before the curtain finally rises on a scene of unparalleled calm.

The turbulence of July is a little different from that produced last April by the initial effort to draw up a plan for welfare reform. Then, the internal bureaucratic struggle was over the fundamental character of the program Jimmy Carter would pursue would it be a work-and-jobs program or a cash-assistance program, a relatively frugal plan to improve existing welfare systems or an audacious (and costly) guaranteed income scheme? The answer was some of both. So this time around the issue has not been so much one of jobs versus cash as of finding the cash to pay for the reform that is emerging.

That is what the noisy backstage conflict that keeps recurring between HEW and HUD is about whether some HUD programs for the poor can either be "cashed out" or otherwise altered to compensate for some of the funds that a new welfare program would be expending. This and a variety of other disputes will presumably be resolved by the President either at a meeting on welfare scheduled for Thursday or in the days immediately following. But the general outline of the plan favored by his administration is already clear: a combination of jobs and cash grants that provides assistance to the working poor as well as to those unable to work, one that provides a relatively high federal contribution to welfare payments and which also pays part of the states' supplementary contribution, and one that underwrites public jobs when private employment is unavailable.

The catch is that there is no part of this that is not very expensive, or at least potentially so, and the President has directed Mr. Califano and company to come up with an efficient, humane proposal that stays within the confines of current welfare expenditures. And it is largely for this reason that there has been so much bureaucratic hustling and rustling backstage as an attempt is made to find the funds to provide the program Mr. Carter has in mind. In truth, at the level of current welfare spending, you can't get a program of the kind Mr. Carter has outlined except at the expense of either large numbers of welfare recipients or of the states that are looking for some fiscal relief.

The point suggests an obvious dangers and conclusion to us. Nothing would be more normal in the culture of government than to try to fulfill the President's wish by a lot of bureaucratic and fiscal legerdemain - account juggling and program mirror-tricks to make it seem that the whole thing can be done at zero cost. But nothing would be more reckless, either. Washington has been through that once with the Nixon welfare-reform show, and once was plenty. This time around we hope the President will be open and direct about what you can and can't get for the money he is proposing to spend. That is the only way he will even have a fighting chance of getting his program through - and such candor in high places on the subject would in itself constitute a kind of welfare reform.