This is my 86 3/4 ton burb. I love this truck!
Since i bought it feb 2008 i have replaced the stock qjet carb with an Edelbrock 600cfm 4 barrel that sits on an Edelbrock performer intake manifold,  installed thermo wrapped summit headers, installed 2.5" straight exhaust to dual high flow Thrush mufflers, added a 4" Rough Country lift with 315/75/16 Pro Comp A/Ts as well as 2" add a leafs in the rear. Completely removed all smog and emission components as well as A/C pump and radiator. Installed a new Napa water pump and power steering pump. All hoses have been replaced xcept for the heater hoses. Plugs wires and distributor cap and rotor are new and new valve cover gaskets. Oh and a newer style GMC steering wheel and stereo, speakers, high lift jack, extra gas can, tool box, and survival gear.
The future for this rig involves new oil pan gasket with a high volume oil pan, rear main seal (if its a 2 piece but i think its 1), trans gasket as well as high volume trans pan, and lower gear ratio, Ujoints and the list goes on and on. I would also like to find a roof rack and aluminum 16x8 wheels to mount some new Firestone Destination M/Ts on...
As of right now the truck doesnt see much trails however after beefing up a few components it will be ready. The motor and trans are strong (350 th400) and the low range 4 wheel drive is amazing.