engine high on driver side

I leveled the car today, the best I could and ensured the garage floor was level-ish but close. by using a 6 ft. Level and measured from the k mem. Bolt to the top of the level that was on the floor and my findings are the driver side frame rail is 3/8 higher then the passenger side ...I'm not sure if there is tolerance built in to the car for that , being that it's an all steel car