BB6 should weigh 77958 tons to go 37 with .2 belt which is around 1650 tons trimmed from taking off 1 bind on each gun reduces weight by 945 tons what ever is left is taken off the crew.
BB5 should weigh 62213 tons to go 39 with .2 belt which at level is easy just take 1 bind off each gun at level 120 you got to trim about 500 tons off crew on top of taking 1 bind off each gun.
Delay classing comes down to your reps crazy reps you wont have to but decent reps you will need to delay class. By crazy reps you will need like 250+ vets and elite if you have 3 and maybe 200+ if you got 4.
EDIT: Had 77598 tons should have been 77958 tons