Trying to lighten the truck, what can I do?

To aid in your searching travels, may not hurt to chat with a new truck salesman. You may not be buying a new truck from him today, but for all he knows what your doing could lead to truck sales in the future, so hopefully they would be helpful. They should have a pretty close idea of weight differences, as well as working performance and recommendations / allowances between 5/16, 3/8, double frames, etc. You don't want to be too lightweight for what you're doing, but you don't want to be to thiccc either!

 

My '80 was sleeved where the rear suspension sat. Rust jacked but still got it out. HUGE pain in the ###. Took about 2 days with sledges, bars and a torch.