Invicta grammar and Valley Park community schools in Maidstone will remain separate. They will keep their own heads, who will be responsible for the day-to-day running of the schools.
They will report to a new executive headteacher, responsible for strategy.
Interviews for the pound;100,000-plus post are scheduled for next month.
Sue Glanville, the existing executive head, said merging the governing bodies in March would open the way for further change, such as sharing newly-qualified teachers, and combining sixth-form classes. She said financial and site management could also be combined. "There will be all kinds of opportunities for staff to co-operate and offer a wider range of courses."
Mrs Glanville said the schools had been co-operating for almost two years.
Since then, she said, the head of English at Invicta had helped to raise the percentage of boys at Valley Park getting a C or better in English language GCSE from 23 per cent in 2004 to 51 per cent this year.
Vic Ashdown, head of Valley Park school, said the relationship worked both ways. Valley Park, had a reputation for performing arts and had recently led a combined production of a musical at a local theatre.