The bilingual welcome signs designed by Peter Max for the General Services Administration at a cost of $300,000 will be installed at Canadian and Mexican border stations as originally planned.

The murals, which have been in storage for several years, were previously rejected by the U.S. Customs Service because of the flowery and cosmic nature of Max's art. Customs described the psychedelic figures which glide across the colorful posters as "inappropriate," and said they seemed to symbolize the drug culture of the '60s - an image contrary to the border officials' job of stopping drug traffic.

The new Commissioner of Customs, Robert E. Chasen, announced the change of policy yesterday following intensive lobbying efforts by Jay Solomon, head of GSA, to install the 200 weatherproof signs.

Solomon received encouragement from the White House on this project "to use what we've got." President Carter looked at photographys of the signs at a meeting on Nov. 7, and informed Solomon that he "likes Peter Max's art very much" and felt that the murals were "very acceptable."

Solomon, who describes Max's work as "happy and cheerful," met with Chasen and Commissioner of Immigration and Naturalization Leonel J. Castillo three weeks ago in hopes of reversing the policy. Castillo supported using the signs, but Chasen remained hesitant and agreed to a trial installation.

On Sept. 29, posters bearing the message "Welcome to the U.S." in French and English, were erected at Alexandria Bay, N.Y. and Highgate Springs, Vt. At the same time seven of the signs were placed on easels and displayed at the Customs office building in Washington.

GSA conducted an informal survey and found the response to the murals very favorable. According to Peter Masters, the GSA official who presided over installation, the first driver who crossed the border once the sign was up, jumped out of his car and took pictures.

Responding to the news that the signs will be used as planned, Soloman said, "I'm very excited about it. I think Peter Max has captured the warmth and excitement of America with these signs, which we hope will be felt by all people entering this country."