72 LWB with leafs, need to be educated

[72LSLB]

Got under my 72 C10 lwb last night to get a closer look at the suspension components out back. My truck has leafs, which I'm told are rare for a chevy truck, but standard on a GMC. My truck has been lowered approx. 5 inches front and back, the back was done with an axle flip kit and the frame was c-notched. It currently has crummy Monroe shocks on it that will be getting replaced by Belltech street performers.

There's currently no other hardware back there, like a panhard rod or trailing arms. I believe the coil spring rears have panhard rods?
Is there anything else I can add out back to help the cornering/ride of the truck? I also noticed the shock mount on the frame has 2 different locations; the shocks are currently in the most rearward location. If I can be directed to a link that explains the rear suspension on a leaf spring 67-72 truck it would be greatly appreciated; and also if I could be directed to the best bang for the buck add-ons that would also be great. Thanks!