(FORTUNE Magazine) – IN THE GALAXY of Washington think tanks, the archconservative Heritage Foundation is eclipsing its rivals. From privatization to Star Wars, Heritage prescriptions have become Reagan Administration policies. Indeed, Heritage so closely mirrors the far right within the Administration that Soviet Leader Mikhail Gorbachev lambasted it before the Politburo last November as the ''ideological headquarters'' of the ''American extreme right wing.'' Says Heritage President Edwin J. Feulner Jr., with undisguised glee: ''That's just where we want to be.'' Feulner, 44, sees his organization as ''the shock troops of the conservative movement.'' Instead of peopling Heritage with the luminaries from government and academe that the Brookings Institution and the American Enterprise Institute attract, Feulner brought in zealous young thinkers, many of them recent Ph.D.s, who personally push their ideas to congressional aides, the Administration, and the media. Says Heritage Vice President Burton Pines: ''Everyone here is an advocate. We're here to do battle.'' In the Seventies Heritage ran a distant third in influence and prestige to Brookings, the bastion of intellectual Democrats, and AEI, the establishment voice of neoconservatives. But Heritage's scrappy strategy proved exactly right for the Reagan years. Heritage's brand of conservatism is mostly to business's liking -- but not always. Strong opposition to quotas, for instance, cost Heritage a number of large steel and textile contributors. And Heritage blasted a Pentagon proposal to build a new cargo plane designed by McDonnell Douglas, a big contributor. Instead, it advocated upgrading one built by Lockheed, a modest donor. But ideological purity has not hurt financially. Launched in 1973 from the second floor of a Capitol Hill townhouse with a $250,000 grant from beer magnate Joseph Coors, Heritage now owns an eight-story headquarters overlooking Senate office buildings. Last year it raised $11.2 million, approaching AEI's $12.8 million and Brookings' $12.4 million. Unlike its rivals, Heritage relies heavily on individuals for support. Individuals contributed about 38% of its budget last year, vs. only 15% at AEI. Neither AEI nor Brookings plans to hawk its wares in the Heritage style. But others are following fast in its footsteps. On the right, the libertarian Cato Institute is adapting Heritage's activist techniques. And liberal economist Jeff Faux is trying to replicate Heritage's success on the left with his new Economic Policy Institute.