[surfamtn]

Hello gang, sorry if this has been covered in previous posts:\
I'm looking to lower my 1966 1500 (three-quarter ton) that has rear leaf springs. I would like to achieve total of about 4 inches drop in the back, I was planning on taking a couple of leafs (3 leafs to get 1.5inches) out of the springs and using the after market drop shackles to get another 2 1/2 inches. I don't need the 3/4 ton capacity so the decrease in spring strength is really no problem. The after market drop shackles are listed as being half ton, so...

The question I'm wondering is are the widths of the leafs the same?
Are the mounting points the same from 1/2 to 3/4 ton?
I'm planning on changing the shocks same time.
Is there anything else I'm failing to consider?