Yes you can put 6-7 gals more than spec.

If you have heard of the harpoon mod this will help filling full without waiting for the foam to go down.

33 gals I wouldn't let it get that empty . Injectors on a 6.0 need all the fuel they can get .


BTW I just assumed you had a diesel when you said you had to wait for the foam to die down . If your a gasser don't worry about it.