I just got my project on the road for the first time.
The history. It's a 1983 1/2 ton 4x4 c6 auto. It was owned by the county. Bought at auction with 65000 miles on it. It had sat for quite some time. The guy I got from got it started and had a small engine fire. I bought it from him and found most vacuum lines broken or melted. The smog pump wasn't hooked up but was still on the truck. All the wires going to the solenoids on the carb were melted.
Here is what I did. I pulled every vacuum hose. I removed the solenoids from the carb and laid them off to the side. I removed the smog pump and and screwed a pipe plug in where the big hose was supposed to hook up. It had the cat converter removed.
I added a new vacuum line from a ported outlet to the vacuum advance. I saved the vacuum line from the manifold port to the firewall that goes to the round ball canister and runs the heater control.
The big line that runs from the carb vent to the square box canister ( I assume charcoal canister) is there but the vacuum valve in that line is split in half. I got it running and warmed up and took it for a drive. It seems to run smooth and pulls great but at part throttle pulling a hill it will ping. The EGR is all there but there is no vacuum line to the EGR vacuum pot.
Where should that vacuum line go?
I'd sure like to keep the smog pump off this ole truck but I'd like to make the egr work.
I know nothing about the egr valve but the big pipe that goes from the manifold to the egr is still intact.
This is an AC truck and I know one of the solenoids is for that. I think the other is cold start fast idle. both of those solenoids are melted.
I also need to get the choke working. It still has the small line from the exhaust manifold to the choke housing intact and it still has the cloth cover.
Some of the AC lines were melted so for now I removed all those and the compressor.
I have searched for days and have learned quite a bit but not finding exactly what I need. It's a non feedback carb and duraspark 2.

 

I drove it 40 miles today. I filled it up with premium and it ran better. It never did ping on this trip. It had about a quarter of a tank full of dated and fresh 87 octane mix. I don't know if that was the problem or not. I don't wish to have to run premium. I need to know where to get my dizzy re-curved or details and a parts list to do it myself. I also would like to know the propper place to run vacuum to the EGR and see it that would make the pinging stop.

 

Check to make sure the vacuum advance is actually plugged into the right port. Rev it a bit and see how the arm moves (next to where the line goes into the distributor). If it doesn't back down when it returns to idle you probably have it on the port.

Maybe try loosening the distributor hold down nut and back the timing a few degrees. Do you have a timing light? If so see what it's at when idling.

Check all over for vacuum leaks, mine was notorious for them when I was running the stock carb setup. A lean mixture may cause pinging.

 

I set the timing at 10 deg while idling with the vacuum advance unhooked and the port plugged. The port I hook the vac advance pulls no vacuum at idle but picks up with some throttle.