If President Reagan is reelected, look for no surprises in his Cabinet after the election. That's the latest view of White House aides, who say that Reagan is unlikely to ask for any resignations.

The announced departure of Attorney General William French Smith is likely to occur as soon as possible; Reagan will quickly renominate White House counselor Edwin Meese III to head the Justice Department. But Reagan aides expect the rest of the Cabinet to stay put until late 1985 or 1986.

They expect Treasury Secretary Donald T. Regan to remain at least until the tax-simplification effort is fully launched. They expect Office of Management and Budget Director David A. Stockman to stay at least until the next round of budget battles is over. They don't expect Reagan to replace Labor Secretary Raymond J. Donovan while his legal problems are unresolved.

Aides also believe that Secretary of State George P. Shultz will remain; expectations are mixed about Defense Secretary Caspar W. Weinberger. CAMPAIGN POINT MAN . . .

Insiders say that Reagan will do what he can for GOP congressional candidates in the final days of the campaign but that Vice President Bush may be the point man.

Reagan aides will decide this week how much effort to devote to congressional races. The current thinking is to use Reagan's time sparingly but to send Bush out with a new schedule devoted to helping Capitol Hill hopefuls.

They are also toying with the idea of trips to selected states where a Reagan appearance would make a big difference.

Some aides want Reagan to stress the need for a Republican Congress but avoid direct attacks on Democrats who may be needed in coalition-building if Reagan is reelected. NOFZIGER RETURNS . . .

Veteran Reagan press secretary and political adviser Lyn Nofziger returned to the Reagan campaign plane briefly this week, riding Air Force One out to California. Nofziger, now a private political consultant who also helps the Reagan-Bush committee, was sporting one of his many Mickey Mouse ties, and was asked by a reporter whether he should be described as a Reagan "adviser." No, he said, "hanger-on" would be just fine. WHISTLE STOP WITH A DIFFERENCE . . .

Reagan's campaign train tour across Ohio on Oct. 12 had many nostalgic touches recalling Harry S Truman's 1948 whistle stops, including speeches from the back of the old U.S. Car One against a backdrop of small-town scenes that could have been painted by Norman Rockwell.

But anyone who imagined they were seeing a rerun of the 1948 campaign needed only a closer look at the baggage car. It was carrying highly sophisticated communications gear so that Reagan could reach across space and the oceans.

As the train wound through the rustling cornfields, Reagan spoke to the astronauts aboard the orbiting space shuttle and placed a transatlantic call to British Prime Minister Margaret Thatcher after an explosion ripped through her hotel in Brighton.

The politicking was old-fashioned, but presidential travel has become far more complicated than in Truman's day. The 200-mile day-long trip cost the Reagan-Bush committee about $300,000. When the vast security apparatus is counted -- including several hundred Secret Service agents who guarded the route -- the price tag was probably over $1 million.

Reagan spoke from the rear of the heavily armored presidential car, which is outfitted with gold-plated chandeliers and ivory ceiling. It is owned by the Gold Coast Railroad, a nonprofit group of railroad enthusiasts in Fort Lauderdale, Fla.

Truman's campaign was viewed as so hopeless in the summer of 1948 that many reporters didn't bother to leave the train and sample reactions when he spoke. Only the photographers got off.

If he could have joined Reagan's "Heartland Special," Truman surely would have noticed the difference: hundreds of reporters crowding off the train at every town to hear essentially the same speech and scrambling in another baggage car to transmit Reagan's words across the nation via computers linked to telephone lines.

Truman might also have been amused to find the reporters playing back a scratchy tape-recording of Reagan's own radio broadcast that year passionately endorsing Truman and inveighing against the Republicans.

Aides viewed the Reagan whistle stop as so successful -- after his faltering Louisville debate performance -- that some White House officials considered repeating it in a trip from Los Angeles to Santa Barbara. But the idea was scrapped because of the cost.