They surpassed the previous record of 263-5, set by Royal Challengers Bangalore in 2013
The 51-year-old will step down from the cricket committee, which was formed in March last year, due to commitments that could make it difficult for him to spend the required amount of time for the committee, SLC said in a statement.
"For someone like Aravinda cricket is a full-time occupation," board president Thilanga Sumathipala said.
"It's understandable that he needs to prioritise his personal commitments -- he has supported the strategic vision of this administration and been vastly instrumental in many of the developments we have made.
"We intend to continue to engage Aravinda's expertise in our key cricketing activities on a consultancy basis."