CREATE TABLE table_70743 ("Year" FLOAT, "Chassis" TEXT, "Engine" TEXT, "Tyres" TEXT, "Points" FLOAT)

What are the highest points that have a Mugen V8 engine and happened in 1991?
SELECT MAX("Points") FROM table_70743 WHERE "Engine" = 'mugen v8' AND "Year" = '1991'
SELECT MAX("Points") FROM "table_70743" WHERE "Engine" = 'mugen v8' AND "Year" = '1991'