lower the back without losing any spring

[JointTech]

whats the best way to lower the back of my truck 2" without losing any load carrying ability? 72 C20. It has rear leafs. I searched around for a drop shackle and couldnt find one for our years...

so I could rearch my springs.

I could remove that thick short bottom leaf and get about an inch. I dont want to take out 2 leafs though.

I could throw about 500lbs. of concrete in the bed.

my front is perfect and i dont want to lift or lower it any.