Miami — The piles of cash - dog-eared $5, $10, $20, $50, and $100 bills - are so huge that even hardened law-enforcement officers raise their eyebrows at:
* $667,000 stuffed inside the canister of an industrial vacuum cleaner in a car headed out of the United States.
* $273,000 inside a gray Chevrolet in southern Florida.
* $899,000 in just one Florida house.
* $334,000 in a Corvette sports car.
* $346,000 in the luggage of one court defendant leaving Miami for Panama.
These are ''narco bucks,'' or ''coca dollars.'' They come from US street sales of illicit drugs. They line traffickers's pockets; bribe pilots, crews, police, and bank officers; and buy the latest, fastest boats and planes.
And they might just be the traffickers's Achilles' heel as well - though efforts to trace smugglers through their profits are difficult and slow.
''If we can trace the money back to the principals, we stand a chance,'' says Stanley Marcus, United States attorney for the southern district of Florida, in an interview in Miami.
The main weapons the US wields are federal laws that require banks to report every deposit and withdrawal of $10,000 or more, and every departing traveler to declare $5,000 and above.
''We're not talking about millions of dollars here,'' Mr. Marcus says.
''No, we're talking about billions, run by foreign cartels - Peruvians, Bolivians, Colombians.
''We're talking about amounts so big that they are comparable to petrodollars.''
His office has aimed at both ends of the drug trafficking pipeline, watching officials and smugglers in countries where drugs originate (Colombia, Peru, Bolivia), transit countries (Cuba, Jamaica, the Bahamas), distribution points (Miami, New York), and buyers (all major US cities).
A vulnerable point for traffickers is when they try to ''launder'' their cash - either through banks into legitimate businesses, or by electronic transfer into banks and tax havens in Switzerland, Panama, the Bahamas, and elsewhere.
In one case, a private Lear jet was said to have taken off from southern Florida bound for Panama City every Friday for eight months. Each time the pilot was alleged to have taken with him cardboard boxes filled with $5 million in cash.
Before he was caught last May 4, the man is said to have flown about $151 million to Panama banks.
The man was indicted in late 1983 on 62 counts.
On Oct. 5, 1981, Humberto Orozco deposited $3,405,230 in cash at the Deak-Perera currency exchange in Manhattan, all in cardboard boxes.
Two days later he deposited another $999,980 in cash. The next day: $537,480. Five days later: $879,000. Three days later: $1,476,420.
The money was being laundered from illegal drug sales. Orozco and his brother were convicted in May 1983.
Eight undercover FBI agents laundered more than $170 million in cash in less than a year and a half, according to FBI Director William H. Webster. Thirty-six people connected with Colombian drug cartels were indicted.
A joint project of the IRS, US Customs, and the Justice Department in 1980 indicted 148 people in its first three years, and seized $33.5 million in US currency.
Seventy-seven people were indicted under a Drug Enforcement Administration operation called ''Swordfish,'' and 17 bank accounts seized.
But low bails and the fact that many traffickers live abroad both block much of the law enforcement effort.
Thirty-seven of the 77 were still fugitives at the end of 1983. Some fled abroad. Others, including Cubans, Bolivians, and Bahamians, live abroad.
Extradition requests to the Colombian government, for instance, yielded nothing by November 1983. Some US officials see a glimmer of positive response in talks with Bogota since then - but not much.
Mexico refused to yield a Colombian called Jaime Guillot-Lara, accused of conspiring with several members of the Central Committee of the Cuban Communist Party to smuggle cocaine and marijuana to the southeastern US.
A former Bolivian minister of the interior, Col. Luis Arce Gomez, remains free although he was indicted with 17 others on charges of conspiring to import hundreds of pounds of cocaine into the US and distribute it from Miami.
Some officials of Florida banks have been convicted. They accepted large deposits in cash without reporting them.
One more problem for traffickers: how physically to handle the money.
One of the many facts about money Mr. Marcus has amassed since his appointment to the southern Florida antidrug task force in early 1982 is that $2 million in $20 bills weighs 235 pounds.
One law enables assets such as autos and bank balances to be seized pending trial. If a trafficker is acquitted, he can petition for his assets back.
The US has some of the most effective seizure laws in the world. The United Kingdom is considering tougher measures. Italy has some of the strongest: assets even suspected of being connected to drug dealing can be frozen immediately.
Assets seized in southern Florida alone in fiscal 1983 totaled more than $20 million. In the Everglades, drug enforcement agents seized 39 vessels, 31 vehicles, and 3 airplanes.