At the George Bush for President headquarters in Houston, a 255-page manual of Federal Election Commission rules and regulations is called "The Bible."

It holds all of man's accumulated knowledge on how to get eligible and stay eigible for federal matching presidential campaign funds.

If the manual is "The Bible," the Bush headquarters building itself is a temple to the FEC rules and regulations. The fund-raising operation is segregated on the fifth floor - because fund raising expenses, including the rent, are to be segregated for FEC campaign expenditure reporting.

The operation devoted to winning Texas' 80 delegates to the 1980 Republican convention is confined to the third floor - because the state-by-state expenditures must be carefully controlled to avoid exceeding FEC limitations.

The national political operation of the Bush campaign is handled separately on the second floor, to avoid commingling it with the other segregated expenditures.

This is the first time that a presidential race will be governed - from start to finish - by the sweeping laws and federal matching fund regulations implemented only partially during the 1976 campaign. The contribution limits, the spending ceilings and the elaborate record-keeping and reporting requirements are now firmly in place for the first time.

And a survey of te 1980 campaigns suggests that at this early stage, at least, the net effect will be to alter significantly the manner in which politicians campaign for the presidency.

The campaigns have become more like businesses - centralized, heavily regulated, and loaded with accountants - with what many 1980 presidential campaign strategists foresee as a sharp decline in the potential for grass-roots participation and state-by-state flexibility.

Compliance with the laws and regualtions has become a time and money consuming preoccuption of the campaigns for better or for worse.

It is for the better, in the view of campaign "reform" advocates and many 1980 presidential campaign strategists, because it requires more careful and creative planning and spending, helps eliminate "fat cat" contributors, and cuts monied candidates down to size. It is for the worse because it greatly complicates the running of a campaign.

"It's kind of a pain in the backside, expensive and time consuming," said Tom Bell, campaign manager for Sen. Bob Dole's 1980 presdential effort. "But its beneficial to us. It kind of gives us parity with [Ronald] Reagan and [John] Connally."

Beyond this, the style of running a campaign is expected to change not only at the national office of a candidate but at the precinct level.

The looseness of a big-city campaign, for example, in which "walk-around money" was freely dispensed to partisan armies of poll-workers and leafleteers, may give way to the tightness of the tightest bookkeeper. "We must now be very specific about such spending," said Donna Sagemiller, controller of the Carter 1980 campaign. "We must leave a very careful audit trail" for the FEC.

"Audit trails." It's enough to make a Baltimore boss weep. But that was, after all, it's design. The only rub is that for every "fat cat" eliminated, an accountant may have taken his place.

To qualify for federal campaign funds, a presidential campaign must first raise $5,000 in each of 20 states in contributions of $250 or less.

To stay eligible, it must adhere to predetermined spending ceilings in each state during the course of the primary season and not exceed about $15 million (a final figure is not yet determined) in total spending up to the nominating convention.

At the same time, the campaigns must obey all the other laws: the $1,000 contribution limit, the $5,000 contribution limit for political action committees, the prohibition on corporate contributions, and so on.

Some of these regulations were in place in 1976 under the newly enacted Federal Election Campaign Act. But the guidelines were fuzzy, if they existed at all, for much of that year, and for part of it, implementation was suspended for a time by a Supreme Court decision that forced Congress to rewrite the entire legislation.

And this year, for te first time, the FEC has placed the "burden" of proving compliance on each campaign.

Officials from the various campaigns estimate that compliance - accountants to keep the records, computers to check them, copiers to copy them, and lawyers to interpret and (sometimes) get around them - will cost at least $1.5 million per campaign up to the time of the nominating conventions.

"By the time the FEC comes in to audit us," said Stan Huckaby, head of an accounting firm that has been retained by Sen. Howard Baker's campaign, "we will have audited ourselves three times. There will be a manual check before it goes into the computer, a check by the computer and another check when it comes out."

All told, some 60 people are currently employed in seven campaigns performing compliance chores, according to campaign officials.

These efforts are needed not only to provide the voluminous reports and records required by the FEC but also to plan campiagn strategy in light of the rules and regulations.

"The need to get out accurate and immediate budget reports on a daily basis has become critical," Huckaby said. Take a state with a spendiing limit of $260,000, for example.

"If you feel you've spent $200,000 and when the real figures come in you've spent $275,000, you may have a problem."

The ceilings, in turn, hold considerable sway over strategy.

A heavy push in the early primaries and caucuses - like New Hampshire, lowa and others - could theoretically exhaust a third or a half of a candidate's overall spending ceiling, leaving little to allocate among the remaining races. A push that is too restrained could mean that a candidate never gets past those early critical stages.

"You have to spend this year doing the minimum you can but still what you need to do," said John Connally's campaign manager, Eddie Mahe. "Dollars spent this year are not available to you the next."

"It's enormously important," said Connally consultant R. Doug Lewis. "If you guess wrong on the spending decision, you may guess wrong on the election."

As a result, the accountants are likely to have expanded roles in campaign planning. "Before the law," said Huckaby, "the last person they wanted in a room before making a decision was an accountant. Now, the accountant is essential."

There is general agreement that the ceilings, the rules and the bookkeeping systems will inevitably cut down on campaign flexibility and grass-roots participation and require much greater centralization.

"In the old days," said Reagan strategist Lyn Nofziger, "you'd tell a guy: 'Hell, go out and raise your own money and spend it.' You can't do that anymore. He can't spend a nickel."

"I've worked in politics before," said Huckaby. "We'd say, 'let's go on a media blitz somewhere' and we'd go out and raise $75,000 and spend it. Now we have to know in advance. We can't start guessing on programs . . ."

"It eliminates grass-roots activity," said James A. Baker III, Bush's campaign manager.

While campaign officials complain about the restrictions, many appear to have applied equal energy to finding ways around them.

Reagan, Connally and Bush each maintained multi-candidate "political action committees" before organizing their official campaign committees.

These operations are able to accept up to $5,000 in contributions from individuals - thus avoiding the $1,000 ceiling. In addition, the spending of these committees - although they clearly aid the candidacy of each man - does not fall within the overall spending limitations.

The FFC, following a complaint from the National Committee for an Effective Congress, is currently considering the legality of such endeavors.

Some campaigns are finding another way around the spending limitations by interpreting the FEC regulations to say that spending for compliance with the law and for fund-raising does not count against the overall spending limits.

Connally's campaign, for example, spent $731,747 in the first three months of 1979, according to its finance reports. According to its own accounting, all but $195,000 of that sum will not be counted toward the spending limits because it was used for "compliance" and "fund-raising."

At that rate, a campaign could spend not the $15 million limit for its campaign but as much as $24 million or $25 million.