Drive shaft rubbing trailing arm crossmember

[Fangio]

I have a 64 long bed 350/th350 with a 3/4 drop from CPP and a one piece driveshaft. With a decent sized load in the bed the driveshaft rubs on the trailing arm crossmember. What are the options to fix this?

I would like to go a little lower all around, does that mean I am stuck getting an aftermarket or modified trailing arm crossmember at some point?

Are airbags in the rear the best option to maintain a decent ride and to be able to carry a load? Thanks.