I would look at the axle and installing some type of spacer between the axle setup and the bottom of the trailer to get the “gap” back that you had with the old axle set up. Then I would next look at the type of boards that bass cat used for your bunks and go with the same type of wood. Allan from parts or Richard probably know what you are looking for or will steer you in the right direction. Remember this, if you raise the height of the boat on the bunks you are then raising the height where the boat touches the front roller, etc. It all snowballs, just like it will effect how the boat loads and unloads on the trailer. If you could send the axle assembly back and go with one from basscat without generating too much cost that would be the way to go, however I doubt that the manufacture of the axle is going to take it back, which tends to make me want to go with building some type of spacer to drop that axle down a bit to gain clearance. I don’t think you need much, probably 1/2 or less for peace of mind.
.
