The chairman of General Motors Corp. today said he isn't concerned about the IRS investigation of possible income tax evasion by the giant auto manufacturer.

"We think that what we have been doing is in full accordance with the law," Thomas A. Murphy said. "We think what we've been doing is right."

In a wide-ranging press conference before his keynote speech to the annual Society of Automotive Engineers Congress here, Murphy also delivered a vigorous and somewhat 1950ish defense of the private enterprise system.

Murphy criticized what he called confusion between equality of opportunity - "what this country stands for" - and equality of results," that requires "everyone to cross the finish line at the same time."

He also said:

Emissions limits for new cars should be tightened down to 0.41 grams of hydrocarbons per mile "as soon as reasonable."

"Some people inside and outside government associate bigness with badness" - and that is a mistake.

American air is getting cleaner everyday and getting rid of older cars will speed that process.

The national economy doesn't need "a great deal of stimulus now" but "I do think we need to continuation of stability."

GM has no plans to raise prices for the balance of the model year, but "everything we buy seems to have gone up."

Murphy has a strong and growing reputation in this town as a man who has been telling businessmen that most of the problems with government and consumers are their own fault. Detroit auto executives also think Murphy is saying they're the ones who will have to change that.

In his prepared remarks for the FAE, he changed his focus from businessmen to regulators who want to prevent the consumer from deciding for themselves "whether to take a risk."

He cited cigarette companies that have to both carry a label about their prouct and "proclaim its danger in their advertising."

Murphy also hit at the administrative law decision on Borden's requiring the company to license it s Rea-Lemon brand name to competitors.

Murphy took small note of the widely broadcast IRS investigation of GM's taxes for reasons that are more easily understood here in Detroit than elsewhere.

The Wall Street Journal said in Tuesday's editions that the issue is about $100 million a year in suspect writeoffs of equipment.

Murphy's relatively casual attitude about such alleged tax evasions - a topic that would drive most business executives up the nearest wall - is only reasonable in the context of GM's history and practices.

In May 1974, this reporter learned a lesson about GM, GM people, accounting and integrity.

In an interview with John B. Cook, now assistant treasurer of taxes, and his boss, Henry W. Welch, who retired in July 1975, said he had received simple instructions on doing the job when he had been made a vice president. "No cutes," Welch said. Just that: "No cutes," meaning adhere strictly to the law.

But what about preventing an Equity Funding scandal, where phony insurance records were manufactured for substantial enrichment.

Cook had a simple, and curiously homespun, reaction back then. Recalled from a then-surprised - really surprised - reporter's memory, his response was this: "What good would it do to steal $3 million or $5 million if I couldn't get credit for it?"