Formally closing the books on a failed revolution, the people of Grenada vote Monday in the island's first elections in eight years.

The voting is for a 15-member House of Representatives and the right to form a new government. It is likely to become a measuring rod here and abroad of the effects of the U.S. invasion 13 months ago that ended four years of rule by Marxist-oriented revolutionaries.

Grenadian and diplomatic analysts say the likely victor and probable prime minister is Herbert Blaize, head of the New National Party, whose supporters include the St. George's business establishment as well as U.S. diplomats and several private American groups backing the intervention.

Blaize, 66, suffers from arthritis and appears frail. But those who know him say he also can be flinty, having grown used to power as chief minister under British colonial rule before Grenadian independence in 1974.

His alliance includes parties formed by George Brizan, a schoolmaster who kept to the classroom during slain leader Maurice Bishop's revolutionary experiment, and Francis Alexis, a university lecturer who organized a conservative exile group on the neighboring Barbados.

The alliance was forged under pressure from other Caribbean leaders allied with the United States, including Prime Minister Tom Adams of Barbados, to block the way of former prime minister Eric Gairy, a mystic autocrat whom Bishop's New Jewel Movement overthrew in 1979.

Gairy's Grenada United Labor Party poses Blaize's main challenge, running on a platform to seek a permanent U.S. presence and introduce horse racing "on a much larger scale than ever before."

Gairy, 62, returned to Grenada from exile in California three months after the U.S. invasion crushed the violent remnants of Bishop's revolutionary leadership. Despite U.S. urging that he stay away, Gairy has sought to drape himself in the mantle of the U.S. takeover, insisting that the island's new airport be named after President Reagan and portraying his party as the only alternative to Caribbean communism.

"We shall remain ever grateful to President Reagan and the American armed forces and all the people of America for the rescue mission," declares the first plank in an election manifesto. "Our national leader, Sir Eric Gairy, has been consistently asking the United States for an American presence in Grenada since 1964."

Another plank promises to permit import of large cars. Because of duty and other restrictions, most Grenadians drive small Japanese or British cars along their narrow, bumpy roads.

Despite his proclamations of affinity for the United States, Gairy could provoke severe U.S. embarrassment if his party obtained a majority and formed the island's government. The former prime minister, a British knight, is often associated here with black magic and his "mongoose gang" of muscled enforcers who discouraged political opposition.

U.S. officials here have said the United States would reconsider its commitment here, including a $57.2 million aid program, if Gairy returned to power. American and other foreign businessmen also have said they are awaiting the election results before making any major investment decisions.

Although most of this has been said in private, the official and private U.S. attitudes are well known in Grenada and have been used as campaign arguments by supporters of the Blaize coalition.

"Several potential investors and 'aiders' have either said openly or, at least, indicated they would turn away from us if the results are wrong," said the Grenadian Voice newspaper in recommending voters to choose the Blaize alliance.

Respecting a pledge made on his return, Gairy is not running personally for one of the 15 parliamentary seats. But if his party wins a majority, his followers say, the wily politician would order a partisan to resign, win a by-election and thus become prime minister again for the constitutional five-year term.

Grenadian analysts predict that Gairy will win several seats on the strength of his past patronage and the organization he had built over the years as a labor union leader and prime minister. Many of the 48,000 registered voters have received cash, gifts or jobs from Gairy or his party.

But Ray Smith, a member of the Interim Council that has been governing for the last year, said the strength of Gairy's organization has become unsure: "With Gairy on the outside, it is impossible to say how many of his traditional loyalists will remain so."

The remains of Bishop's New Jewel Movement, rebaptized the Maurice Bishop Patriotic Movement, also has fielded candidates for half of the legislative districts. However, because of popular disgust with the bloodshed that led to last year's invasion -- including Bishop's own death -- Grenadian analysts give those candidates little chance of obtaining more than one or two seats.

The movement has focused attention on the 250 U.S. troops still here and U.S. support for the Blaize coalition, accusing the CIA of giving campaign funds to the New National Party and providing posters and pamphlets.

One American organization, Conservative Youth, has said it raised enough funds to send two "political coordinators" to help the Blaize group's campaign.

Two other groups, the National Republican Institute for International Affairs and the Free Trade Union Institute, have acknowledged allocating money for the campaign but for what they described as an effort to get out the vote effort on behalf of "democratic forces."

"These are gifts of the CIA," said an editorial in the Maurice Bishop Patriotic Movement newspaper, Indies Times. "Beware."