It looks like the PO disconnected the stock waste gate system.
Myself i would make an adjustable boost control with a spring and bolts.
There may be a reason to return to stock if the computer is upset with the existing configuration.Right now the wastegate will not open,which could cause engine damage without gauges.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews