ABC’s coverage of Monday night’s Academy Awards has been ruthlessly unforgiving of the Nielsen competition, galloping to the best Oscarcast rating in 10 years.The three-hour, 33-minute ceremony, which named the Clint Eastwood Western “Unforgiven” best picture, lassoed an impressive 31.2 rating, 51 share, giving it the highest Oscar rating since 1983′s colossal 38.0/59 (the year “Gandhi” won the best-picture trophy). It’s the third straight year the Academy Awards have improved in rating and the sixth improvement in the eight years since the Oscars hit their low-water mark of a 27.3/43 in 1986 (“Out of Africa”). This is also the first Oscarcast to top a 30 rating since 1984′s 30.3/50 (“Terms of Endearment”). As usual, the length of the ceremony substantially undercut the final ratings average. For the two hours that aired in prime time in the East and Midwest, the average rating was a 33.2. But the 93 minutes that fell after prime time in those regions slipped to a 28.3 rating. The overall 31.2/51 is only good enough for fourth-highest rated telecast of the season so far. The No. 1 slot goes to the Jan. 31 Super Bowl (45.1/66), the runner-up position was taken by the Feb. 10 live Michael Jackson interview by Oprah Winfrey (39.3/56, the top-rated non-Super Bowl telecast in the nine years since post-nuclear holocaust vidpic “The Day After” earned a 46.0/62) and third on the list was the Super Bowl post-game show (32.2/49). There was also a one-minute prime time overrun of the Dallas-S.F. Super Bowl preliminary, which, if counted as a separate program, would make the list with a 37.8/60. The highest Academy Awards rating ever came with 1956′s 46.7/82 (the year “Marty” was best picture). Since 1961, the highest score has been the 43.4/78 in 1970 (“Midnight Cowboy”). The big 1983 rating was the highest in 21 years, since 1972′s 38.7/70 (“The French Connection”). This year’s 31.2 rating marks the first time a post-1983 Oscarcast has achieved a rating higher than even a single pre-1983 telecast. But in fact, this year’s rating tops two pre-’83 awards ceremonies — 1977′s 31.1/63 (“Rocky”) and 1981′s 31.0/58 (“Ordinary People”). ABC estimates that 76 million people saw at least part of the show. ABC’s Barbara Walters interview special, the lead-in to the Oscars in the East and the lead-out in the West, scored a 19.2/31, which is down less than 1% from last year’s Oscar-night Walters spec. The Academy Award Nielsens were a little soft among teen and young-adult viewers. The kudocast attracted a mere 42 share among viewers 12-17, a 43 with men 18-34 and a 57 for women 18-34. By contrast, men over 50 gave the Oscars a 50 share and women over 50 gave it a 60. Thus, NBC’s young-skewing Monday lineup averaged a respectable 11.4/17 for the night, just the net’s lowest-rated Monday in eight weeks. By contrast, CBS’ older-skewing Monday entries sagged to an average 8.6/13, CBS’ worst Monday perf since last summer’s Republic National Convention.