A Pentagon-State Department team flew to Turkey yesterday in hopes of sealing a $450 million deal for military and economic aid to its beleaguered government.

At issue are how much money should be loaned and the extent of Turkish participation in U.S. electronic surveillance of the Soviet Union from Turkish territory.

Turkish monitoring stations took on added importance with the loss of such facilities in Iran, giving the Turkish government extra leverage in seeking more aid than the Carter administration wants to supply.

The U.S. package now under negotiation calls for $250 million in easy-credit loans to buy American arms in fiscal 1980, $198 million in economic aid, and $2 million in military training.

The proposed $250 million in U.S. arms would be an increase over the $175 million provided in fiscal 1979.

The new, higher offer for military aid to Turkey contrasts with the embargo that the United States imposed on arms shipments in 1974 in response to the Turkish invasion of Cyprus.

In a meeting with a group of Pentagon reporters, Adm. Harold E. Shear, commander of allied forces deployed along NATO's southern flank, called that embargo, which was lifted in 1978, "ridiculous."

He said Turkey now needs aid "of Marshall Plan proportions" because of the country's "desperate straits."

Turkish millitary leaders warned bickering politicians there on Wednesday that they must get their act together and solve Turkey's grave economic and political problems.

Shear said Turkey is a reliable ally with a military capable of anchoring NATO's line if given the weaponry and economic aid. "We have got to rebuild the military forces of that country," he said.

"The No. 1 problem within NATO," he said, "is getting Turkey back on her feet." Turkey needs new armor, antiaircraft missiles, ships and aircraft, Shear said. He said it will take "billions of dollars, rather than a few million," to rearm Turkey.

Aiding Turkey will pay off for the whole NATO alliance, the admiral contended. "I will make this flat statement, he said. "Turkey is not going to fall apart. When the chips are down, you'll find the Turks there doing it."