Psst. There is a place where gas still sells for 67 cents a gallon. It is conveniently located. The service is good. And there are no lines.

The only trouble is that the station has only two pumps. And they are reserved for a few bigwigs.

House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), Majority Leader Jim Wright Jr. (D-Tex.) and Minority Leader John J. Rhodes (R-Ariz.) fill up their Lincoln Continental limousines there. So do Senate Majority Leader Robert C. Byrd (D-W.Va.) and Minority Leader Howard H. Baker Jr. (R-Tenn.)

Senate Majority Whip Alan Cranston (D-Calif.) uses the pumps to fill up his government-owned Mercury, as does Minority Whip Ted Stevens (R-Alaska.)

Hardly anyone has even heard of the rest of the folks who use the pumps. George M. White, the architect of the Capitol, for example, has his government paid chauffeur (salary $22,548) fill up the government-owned Oldsmobile that ferries him back and forth to his home in Georgetown. Edmund L. Henshaw Jr., the clerk of the House, has a Mercury limo and a Ford station wagon signed out to him. Both use the same exclusive pumps.

The powers that be like to keep the pumps very hush-hush. Even regular, everyday senators are not allowed to use them.

When a photographer showed up yesterday to take a picture of the pumps, he was told he needed permission to do so from the Capitol architect. When he called the architect's office, he was told he had to have permission of the Senate Rules Committee.When he called the Senate Rules Committee, he was told no dice.

"I don't have authority to grant that kind of request. That's not public territory," said William M. Cochrane, staff director of the Senate Rules Committee. "That's part of the internal working area of the Senate."

Rules Committee Chairman Sen. Claiborne Pell (D-R.I.) later granted permission. But when a photographier arrived on the scene he was again prohibited from taking any pictures.

The pumps are near the entrance to an underground Senate garage at the intersection of Louisiana and New Jersy Avenues NW. That's about three good stones's throws from the Capitol.

The garage is one of those cozy, well-kept structures that Congress has built for itself and its staff. The public pays upwards of $3.80 a day to park in similar digs. Members of Congress and their staffs park free.

That station has two aging pumps. One sells unleaded Esso gasoline to the U.S. Senate, the other sells unleaded Amoca gasoline to the architect's office. In addition to the limos, the pumps provide gasoline to the U.S. Capitol Police, maintenance vehicles and shuttle vans.

Each year bids are opened to suppliers on the gas contracts, according to Elliot Carroll, executive assistant to the architect. The winning bids went for 67 cents last year. That remains the price charged at the pumps. By contrast, service stations in the Washington area charged up to 90 cents per gallon in May, according to the American Automobile Association.

The low prices, however, aren't a break for any of the pumps' users. The government picks up the whole tab, regardless of the price.

The elite station's biggest customer last year apparently was Speaker O'Neill. He spent a total of $1,720 for gas and oil there during 1978. His limo cost taxpayers a total of $27,256 for the year. In addition to the cost of gas and oil, $22,548 went for his chauffeur's salary, $2,450 for leasing the car, and $538 for tires and chauffeurs' uniforms.

Majority Leader Wright spent $26,971 to run his Lincoln Continental, with $1,435 of that going for gasoline. Minority Leader Rhodes spent $26,480, with $1,340 of that for gasoline.

The most controversial autos, however, are those used by employes of Congress. When Rep. Adam Benjamin Jr., chairman of subcommittee on legislative branch appropriations, questioned Capitol Architect White on his need for a car and driver, White replied with a three-page letter relating that the architect has had such benefits for the past 70 years.

Besides, he said, others in his office use the car, and he desperately needs it and his driver for meetings of the D.C. Zoning Commission, of which he is a member. The meetings, he said, are often held "in various parts of the District."

"It has been my practice to use my personally owned automobile for evening meetings and for office use on Saturday and holidays," he added.

When House Sergeant-at Arms Kenneth R. Harding was questioned about the same matter, he replied, "This vehicle is considered an essential tool of the office. A police radio is installed to help me provide more effective service."

He noted that he does not have a government-paid chauffeur and that "all expenses for operation of the car are and have been borne by me personally." Harding's leased Mercury cost taxpayers $1,900 last year.

At least one congressman, Rep. Lee H. Hamilton (D.-Ind.), was unimpressed with the responses. "I don't think any employe of the Congress should have a chauffuered car," he said in a letter to Benjamin. "If there is anything I can do to help bring such practices to an end, please let me know." CAPTION: Illustration, no caption, By Robert Barkin - The Washington Post