Auto industry pricing leader General Motors Corp. today said its 1978-model cars will carry sticker prices an average of $405 above those for current models.

The total included a 5.7 per cent, or $387 increase, on the average equipment car and an average $18 jump in destination charges.

The price move was the first major increase since last fall when the '77s were introduced.

The No. 1 auto maker, which accounts for better than 50 per cent of domestic auto sales, was the first of the four U.S. auto companies to set firm prices on new models. Earlier this summer, GM indicated price increases could be as high as 6 per cent.

American Motors Corp. has set tentative prices $301 to $400 above current models, while Chrysler Corp. and Ford Motor Co. said their prices will not rise by more than 6 per cent.

The price increase raised the sticker on the nation's most popular car - the full-sized Chevrolet - from $4,900.65 for a four-door Impala sedan to $5,282.55.

GM said the price increase on the base models of its '78s, excluding options generally ordered by customers, averaged 4.6 per cent, or $242.

Based on figures furnished by the company, it is estimated that the typical suggested retail price of a 1977 GM car with options was $6,800.For 1978, based on the firm's current sales projections, the average retail price would be about $7,200.

GM also released individual base prices, excluding options, for its new car models except for Cadillacs, the Chevrolet Chevette subcompanct and the firm's new intermediate cars.