Yeah, that's c.1980's GM emissions ******** for you. Your distributor is electronically advanced by the Electronic Spark Control (ESC) system. If you wanted, you could just get a vacuum advanced distributor and hook it up to manifold vacuum. That part's easy to get around on the trucks. The vacuum stuff is trickier in my opinion than just ripping it out because some of it has a purpose. Firstly, you can round file the entire AIR system. That's the control valve, the EFE, the TVS, and all complementary vacuum lines. Since you don't have an ECM, you can probably just block of the EGR port and delete the EGR valve, EGR solenoid, and complementary vacuum lines. The vapor canister serves a good purpose. It latches onto gas vapors instead of releasing them so your engine can have them instead. However, if you want, you can delete the canister, canister control valve, check valve, etc. Be warned that you need a small air filter for that vapor line that goes into the tank if you remove that canister. You also need to place it in a dry place that's not rubbing on or near wires. This is to prevent the tank from taking in filth or water and to prevent you or truck from turning into a roasted skeleton. You'd delete the positive crankcase ventilation and vacuum hose by simply installing a crankcase filter in its place. The PCV does help with sludge buildup and engine blow by. You won't be keeping thermostatic air cleaner so there's one more vacuum line gone. There are various check valves and purge valves that are peppered throughout the system, and they can all go once those changes are made. That should get you down to a bare basic SBC setup. You need to refer to yours or a similar emissions catalyst sticker so you can know about all the trinkets I referred to because there are a ton of them.
