Can you bobtail a class 8 tractor with a class B Commercial Drivers License?

I'm not sure if it depends on the state but based on my knowledge you can not if you are checked by dot they go by your weight of the vehicle or the tottal gwr witch ever is grater so if you have a class B you are limited to a certain anouby of where as with a class A you are not and since most tractors are rated for 80,000 lbs you will be in violation without a class A