My Christmas came a little early this year. I was finally able to convince the powers that be at Toyota that a Regular cab truck needs a rear suspension capable of hauling more than wet laundry and go through a corner without feeling like it is going to fall over.
My dealers Master Mechanic drove my truck and saw first hand that even with no load that it was riding the bump stops. He consulted the Field Service Rep and both agreed to install the TSB springs on my truck. I had already purchased DSM Bilstein 5100s package and had them ready to go on. The dealership installed the rears for free, I installed the fronts. I chose the "0" setting for the fronts and I am glad I did. The ride now is perfectly matched. You truly need the better shocks to compensate for the stiffer springs. This is how this truck should have come from the factory. Given the reputation for the Toyota springs, I realize this is not the total answer, but it is a start.
I took doughnuts to the service manager and mechanic as a way of saying thanks for going the extra mile for me. I have to credit the mechanic, he showed some intriquing ideas on how to quickly accomplish the job.