CREATE TABLE table_71640 ("Year" FLOAT, "Team" TEXT, "Co-Drivers" TEXT, "Class" TEXT, "Laps" FLOAT, "Pos." TEXT, "Class Pos." TEXT)

What was the class when there were 325 laps?
SELECT "Class" FROM table_71640 WHERE "Laps" = '325'
SELECT "Class" FROM "table_71640" WHERE "Laps" = '325'