The plush downtown Sheraton is one of Boston's leading convention centers. And to the gathering planned there for the weekend of March 6 has received little more than standard attention. But the end result of the traditional convention activities-glad binding, speech-making and merry-making-will probably be more significant than most of the hotel's staffers have seen. The 1000 men and women attending the convention will recommend a Republican candidate for governor.

The voters of Massachusetts will not select their next Governor until November and one could hardly complain that the campaign has thus far gotten too little attention. But, ironically, the same commentators who have already devoted countless pages and hours to the process of selecting a Democratic nominee have virtually ignored the G.O.P. half.

This imbalance stems from several factors. Three strong, conflicting, well-known candidates-Gov. Edward J. King, former Gov. Michael S. Dukakis and 14, Gov. Thomas P. O'Neill III-vie for the Democratic nomination. The Republican spot is sought by five relative unknowns-Westwood businessman John R. Lakian, House minority leader William G. Robinson, assistant House minority whip Andrew H. Card Jr., former Boston city councilor John W. Sears '52 and former Metropolitan District Commissioner Guy Carbone.

And while these five contenders have debated several times-they face each other tonight at the Law School-none has clearly staked out a position or even a few key issues. All have attached high taxes, but some have come out with specific substantive proposals. They appear to be fighting for positions on the spectrum.

Furthermore, while delegates to the May 22, Democratic convention were selected in open caucuses earlier this month-increasing the politicking and hence the visibility-delegates to the Republican convention were handpicked privately by local party officials.

The most important reason, some argue, is that in heavily Democratic Massachusetts, the Republican side just doesn't make a difference.

Traditionally, that superficial assessment hasn't been true. While with the exception of President Reagan, the state has voted for every Democratic presidential nominee in the past 20 years, Bay State voters have chosen Republican gubernatorial candidates is more than half the elections during that same period.

This year, however, the party seems hard pressed to provide a strong candidate. John Becker, head of Becker Research Corporation, a state-based public opinion firm notes that "if you go back to the '60s and '70s the Republican candidates were well-established Republican leaders." And though Becker will take on duties advising Lakian's campaign, he adds that this year "the Republicans are distinguished primarily by the fact that these are very obscure candidates."

Nevertheless, these "very obscure" men are already jockeying for a position they insist could propel them to the Statehouse.

It is still difficult to predict who will receive the convention's non-binding endorsement in two weeks, but all sides agree it will come down to Lakian and Robinson. Lakian, who has no political experience and to playing up his "untainted" image, has been organizing for these years.

Robinson, the opposition leader in the legislature, has encouraged speculation about his ambitions for equally long.

It is even more difficult to entries the convention's impact. The official Republican nominee will not be selected until the September primary Lakian, confident of victory, has said he will drop out of the race if he does not get his party's imprimatur. Aides like to point out that every successful Republican nominee in the past few decades has had his convention's support Robinson has said he will light to the end; his staffers contend that the convention is too early in the race to make a difference.

And aides to the other candidates who have put very little effort into the convention also play down the event. "Conventions normally endorse conservatives," says Michael Mutter Card's deputy campaign director. His candidate hardly fits that description. The 34 year old representative has a reputation at a "coalition builder." with support ranging from Francis W. Hatch Jr., the liberal Republican nominee in 1978 to conservative economist William Simon.

Sears-who has held five government jobs since 1964, and who run for secretary of state in 1978--is trying to position himself as the front runner, the candidate who doesn't need the convention for recognition. He likes to refer to polls publicized late last year which show him with the largest name recognition and support."

But, as pollster Becker points out, 31 percent visibility is not very significant and hardly insurmountable.

Strategists for Sears, as well as for the other candidates, express confidence in getting the nomination, but all are more shaky when discussing the election. Most agree that this time around the Republicans chances hang more on the outcome of the Democratic fight than on anything they can do. Even a lightweight contender could challenge the Democrats if King. Dukakis and O'Neill bloody each other enough before the primary. And that observers say, is not unlikely