The Carter administration promised yesterday to give Congress a complete proposal for an energy mobilization board today in an attempt to get legislative action by early next week.

Despite the promise, there appeared to be at least some differences between the White House and Congress over the proposal.

The White House agreed to deliver its proposal after a series of meetings between President Carter's staff aides and key congressional leaders. The action was an attempt by Carter to avoid having Congress act on the energy mobilization board before the White House came up with its own plan.

Proposals calling for speeded-up authority for energy projects are pending in both houses of Congress.

Much of yesterday's discussions centered on points of disagreement between the pending congressional proposals and the White House plan, which was still in very general form.

The disagreements outlined by both administration and Capitol Hill sources include the authority the federal board would have to circumvent state and local procedural rules and the number of projects that could be affected.

Rep. Morris K. Udall (D-Ariz.), chairman of the House Interior Committee, has proposed, for example, that only six projects be allowed to "fast-track" through the regulatory maze at one time.

The Senate has no limits, and the administration will call for more than six, according to a White House source. Environmentalists are opposed to anything above six.

Udall's bill does not provide for any type of mobilization board, but there appears to be little problem incorporating that concept into his proposal.

Both sides stressed that they are not calling for authority to override any substantive environmental regulations. They say those must still be complied with.$&(WORD ILLEGIBLE

They did say, however, that there will be efforts to shorten the time various regulatory authorities will have to pass judgment on proposed projects. If those agencies do not respond in the shortened time frames, they say, the mobilization board will decide for the agency - but still not allow any violations of environmental rules.

There appears to be agreement on another proposal that would force any court challenges to the chosen energy projects immediately to district appellate courts, thus cutting considerably the time spent in court.

As with the environmental rules, the board will not attempt to influence the final court decision, but merely attempt to hasten it.

The administration also has proposed that the board be able to waive the application of environmental rules adopted after construction of the project has begun. In other words, the designated projects would be "grandfathered" and protected against post-construction delays.

Although no similar provision is included in the congressional proposals, there appears to be no major Hill opposition to that proposal.

Udall, in meetings with White House aide Stuart Eizenstat, stressed the fears of environmentalists that the board would be a "Trojan horse to dismantle environmental laws," one source said.

One administration environmentalist said for example, that some of the so-called procedural requirements that could be waived by the board would be the provisions of the National Environmental Policy Act, which mandates environmental impact statements. CAPTION: Picture, MORRIS K. UDALL...proposes six-project limit