In these last final weeks of the presidential primary season, GOP front-runner Ronald Reagan is finally picking up the support of one group that has long eluded him -- the corporate boardroom crowd.

Nowhere has that been more clear than in Reagan's campaign swing through this hard-pressed city the last two days. The former California governor has raised $330,000 for his campaign coffers and rubbed shoulders with some of the biggest movers and shakers in corporate America.

This noon, for example, he sat between Thomas Murphy, chairman of General Motors, and William Agee, chairman of Bendix Corp., at a meeting of the Detroit Economic Club. Agee introduced Reagan to the crowd of businessmen as a man of "vision and courage." And the crowd of more than 1,200 gave Reagan a standing ovation.

The $1,000 fund-raising dinner Wednesday night was even more impressive. It was put together in just eight days by two of Detroit's most respected financiers, Max Fisher, one of former president Gerald R. Ford's most ardent backers, and Robert Evans, John B. Connally's former Michigan chairman.

The guest list included top executive officers from General Motors, Owens-Illinois, Burroughs Corp., Marathon Oil, K-Mart, Ford Motors, and a host of other companies. Henry Ford II didn't make it, but he sold $10,000 in tickets, Fisher said.

Reagan's first solid show of strength in corporate America came at a time when he's trying to appeal for votes from blue-collar workers in next Tuesday's GOP primary.

He is using the same basic approach to court the two groups at opposite ends of the economic spectrum. He is telling them the Carter administration and the bureaucrats in Washington are strangling the auto industry.

After lunching with a group of unemployed auto workers in Flint Wednesday, Reagan issued a statement charging:

"The Carter administration has conducted what amounts to a concerted campaign to cripple the American auto industry . . . This Carter plan for unemployment, despair, high taxes and high prices must be replaced. We need a program to get the economy moving again, a program which will help the auto industry rebuild."

Before the Economic Club today, Reagan took a similar tack, saying:

"The U.S. auto industry is virtually being regulated to death . . . The auto industry remains the best in the world. It simply needs the freedom to compete, unhindered by whimsical bureaucratic changes in energy, environmental and safety regulations."

This is the same basic message Reagan has been delivering on the rubber chicken circuit for two decades. But with the auto industry facing one of its worst slumps in history, the appeal is broader than it once was. "His message has not changed," Bendix' Agee said today. "We have."

Reagan has demonstrated a clear ability to attract support from blue-collar workers in industrial states, and he is counting on them in the Michigan primary.

He has had less success in corporate boardrooms. Connally, the former secretary of the treasury, originally was the favorite of the boardroom crowd. When he dropped out of the Republican race, Reagan and George Bush, his last remaining rival for the GOP nomination, picked up scattered corporate support.

But Wednesday night's effort was the largest single display of corporate support for Reagan, according to campaign officials in Los Angeles who had originally opposed the Detroit fund-raiser because they feared it wouldn't raise enough money.

In his speech today, Reagan talked of a "new coalition of shared values," emerging around his candidacy, a coalition combining labor and management. Here in Michigan, the UAW and the management of Chrysler, who lobbyed together for the federal bailout bill, understand what he means.

The auto industry, the heard of Michigan's economy, is in desperate shape. Sales of domestic autos are off one-third, unemployment is 12 percent in Michigan, and 15 percent in Detroit.

To help the industry, Reagan has proposed lowering interest rates to make it easier for people to buy cars, putting a moratorium on all safety and environmental regulations, reducing corporate and individual income taxes, abandoning Carter's 10-cents per gallon oil import fee, and forming a task force to develop "a new American strategy of competitiveness."

Gains in auto safety have been due to "the industry's own initiatives," not pressure from consumer groups, he said. "When Ralph Nader charges Detroit ignored safety, who thought of such things as headlights, tail lights, brake lights, windshield wipers, four-wheel drive and disc brakes?"