The state Republican party chairman yesterday urged the Montgomery County Council to keep County Executive Charles W. Gilchrist from proceeding with a plan to remodel management of the county's troubled Department of Liquor Control.

Highlighting the latest crop of questions surrounding the liquor agency, which auditors say is plagued by "gross mismanagement," GOP chairman Allan Levey said: "If someone is going to change the Department of Liquor Control it shouldn't be the people who caused the problems. Until the investigations are complete the Department of Liquor Control should not be allowed to spend one more penny to implement new liquor programs."

The department is the focus of a grand jury investigation. Last month Gilchrist endorsed all but one of the findings of a $125,000 study by Touche-Ross and Co. which made dozens of recommendations to improve the management of the department.

As well as attacking the Democratc executive's handling of the affair that has come to be known in this civic-minded suburb as Liquorgate, Levey chided Gilchrist for his continued friendship with one-time department head and liquor czar Charles Buscher.

And, promising "new developments" at the midmorning press conference yesterday at the Bethesda Marriott, Levey drew into the picture the Congressional Country Club where Buscher is a member along with Sam D. Chilcote. Chilcote, president of the Distilled Spirits Council of the U.S., sits on the county's Alchoholic Beverages Advisory Board as a representative of nonindustry viewpoint, and, according to Levey, he figures prominently in the large liquor purchases at Congressional Country Club.

Buscher, a close adviser to Gilchrist on liquor matters who authored a Chamber of Commerce study on the department which Gilchrist adopted early in his administration, pleaded guilty to liquor violations in West Virginia in 1978.