Eight months ago, the Independent Petroleum Association of America put Bill Kennedy, a relatively obscure Republican candidate for Congress in the San Jose suburbs of San Francisco, on its list of "Wildcat Prospects."

The endorsement signaled a decision within the independent oil community that the Kennedy campaign has the potential of fulfilling a key goal: the defeat of a liberal member of Congress, in this case, Rep. Fortney H. (Pete) Stark (D-Calif.).

The decision represented a sizable gamble, because Kennedy had lost to Stark in 1980 by a 12-percentage-point margin. But the gamble did not scare off the oil community's political contributors.

Just before the endorsement of Kennedy was announced, the Dallas Energy Political Action Committee (PAC) contributed $5,000 -- the maximum allowed -- to Kennedy. In February, the Louisiana Energy National PAC contributed $5,000. W.C. Pickens and R.H. Pickens, partners in the Dallas firm of Pickens Oil and Gas, kicked in $500 each; Louis A. Beecherl Jr., honorary chairman of Texas Oil and Gas, put up $1,000, and a number of other independent oilmen and PACs followed suit, providing Kennedy's campaign with a vital, early pump-priming of at least $20,250. Through July, Kennedy reported to the Federal Election Commission that he had raised a total of $141,108 from all sources, while Stark had raised a total of $170,235.

The ability of a challenger like Kennedy to run a financially viable campaign against an established incumbent is part of a major change in the financing of political campaigns that has taken place over the past four years.

Some of the major elements of this change include:

* Business and conservative groups viewed each other with suspicion as recently as 1978 -- business was regarded as willing to sacrifice principle for profit, while conservatives were often branded by business as being too rigid to compromise. Now the two have joined forces in most of the key, marginal races,, usually behind Republican candidates.

"There is a coordinated passing around of polling information between Republican committees, candidates, groups like ours, and the corporate PACs," said Paul Dietrich, of the Fund for a Conservative Majority. "People talk about 2,000 or more PACs, but the truth is that there are only about 45 corporate PACs, 6 conservative PACs and 15 to 20 trade association PACs that really count . . . a group of less than 75 people."

* The 1974 election reforms enacted in the wake of Watergate have not only encouraged the massive growth of political action committees, but they also have encouraged the emergence of a new kind of political figure: men and women who specialize in directing the flow of political money to campaigns, in effect a new kind of political boss.

These people include Bernadette Budde, of the Business-Industry Political Action Committee; William C. Anderson, senior government relations representative for the Independent Petroleum Association; Richard Thaxton of the National Association of Realtors; Clyde A. Wheeler Jr., vice president for government relations of Sun Co.; and Peter Lauer of the American Medical Association.

They not only have direct leverage over campaign funds, they also influence others making decisions on where to give money. The recommendations of Budde's BIPAC, for example, are followed by business groups across the country.

* There is an increasingly strong set of personal ties to the GOP within key elements of the campaign finance structure. Neil Newhouse, political director for the Chamber of Commerce, is former director of field operations for the Republican National Committee. Morton C. Blackwell, former head of the conservative Committee for Responsible Youth Politics and employe of conservative fund-raiser Richard Viguerie, organized regular luncheon meetings of conservative PACs before the 1980 election to determine election strategies; hired by President Reagan to work in the White House office of public liaison, he continues to run the luncheon strategy sessions for the conservative PACs.

Thaxton of the National Association of Realtors political committee is a former employe of the Republican National Committee and of the Republican Governors Conference. Lee Ann Elliott, former associate director of the American Medical Association's PAC, was appointed by Reagan to a six-year term on the Federal Election Commission.

* Sun Belt interests appear to have become the most aggressive private-sector forces in national politics. Although oil -- particularly independent oil (as opposed to the major oil companies) -- is the most prominent in this assertion of political muscle, it is also present in Sun Belt construction, banking and a host of other interests.

Early in the 1980 Idaho Senate contest, for example, Steve Symms raised $154,000 from Texas interests alone, mostly during a two-day swing through Houston and Midland in his successful bid to oust liberal Sen. Frank Church (D-Idaho). Syms' path is becoming well-worn. For the past two months, conservative congressional candidates from northern states have been flowing through Dallas, Houston, Tulsa, Oklahoma City and Denver at a rate of better than two a week. "Sometimes when it works right, and the guy makes the right kind of pitch, you get $30,000 to $35,000; sometimes you only get $20,000," said Arthur J. Wessely, a Dallas oilman who helps organize many of the events. "Sometimes they try to work it with a fund raiser in Oklahoma City and Houston on the same wheel; they hit two places on the same day."

* Democratic incumbents have extensive financial resources, particularly from unions and a wide range of professional, trade association and business PACs seeking to retain access to members of Congress.

Republicans, however, have the overwhelming edge in resources that can be used to finance challengers and to shore up marginal junior members who have yet to gain a strong hold on their districts. The three basic Democratic Party committees -- the national committtee, congressional committee and senatorial committee -- have raised only $13 million from January 1981 through March 1982 compared with $120 million by the parallel GOP committees.

The result of these various changing spending patterns is that Republicans in marginal contests -- including challengers with no automatic access to Washington-based political contributors -- are able to raise enough money to ensure that they are competitive, while Democrats in comparable positions have no parallel resources.

For example, in the 37 contests where Republicans took over Democratic House seats in 1980, the candidates raised roughly equal amounts in two races, but Republicans raised more in 25 out of the remaining 35. The financial superiority existed although many of the Democrats were committee and subcommittee chairmen, equipped to draw contributions from a wide range of special interests. Republicans spent a total of $10.2 million in those 37 races, while the Democrats spent $7.3 million.

This pattern was recognized by the House GOP freshmen who, on Oct. 30, 1981, sent a letter to all the business PACs declaring:

"We are writing you today as friends of the business community. . . ."Many of us would not now be serving in the Congress were it not for your PAC's campaign contribution last year . . . We all hope we can count on your PAC to make an ever-greater effort to provide pro-free-enterprise business Republican challengers and incumbents the financial assistance necessary to achieve our shared goal of a Republican-controlled House of Representatives."

With this network of support, the GOP is able not merely to protect marginal incumbents, but also to conduct forays into Democratic-held districts, prospecting to see if a major investment would be worthwhile.

In Oregon's first congressional district, for example, Democratic Rep. Les AuCoin (D-Ore.), a moderate-liberal, has all the earmarks of an incumbent with a safe seat. He won by 63 percent in 1978 and by 66 percent in 1980. The recession has thrown Republicans in the timber-dependent state on the defensive.

However, his Republican opponent, William J. Moshofsky, a former vice president for government relations for Georgia Pacific Corp., already has raised $299,105. Key sources of support for Moshofsky have been the business and conservative groups whose goal is not access to incumbents, but an idelogical shift to the right of Congress.

In contrast, Bill McCollum, a freshman Republican representative from Florida's fifth district, may be vulnerable. His seat was altered radically by redistricting, and much of the new territory has been represented by his Democratic opponent, Dick J. Batchelor, who serves in the state legislature. The Republican Congressional Committee warns that Batchelor is a "proven vote getter," and the Chamber of Commerce decribes him as a "strong Democratic challenger." McCollum, however, had a two-to-one fund-raising edge as of July, with $128,158--$79,563 from PACs--to Batchelor's $64,629, of which $2,000 is from PACs.