Classic/Antique Car Repair: exhausted all resources, new distributor cap, factory spec

Question
I have a 1984 Camaro with 2.8L V6 with a 2bbl carb automatic transmission. My biggest problem is that when i shut the key off, it runs on. I have put new EGR components, new carb, new distributor cap and rotor, had the timing checked (by local idiot and replaced the ignition switch, and it still continues to give me trouble. When i first bought it the choke was not working and it didn't do this. Then i fixed the choke and it started doing this. so i bought a new carb and it still does it. I dont think it is the choke because it starts and runs fine. it just wont shut off! any advice would be appreciated. thank you.

Answer
After run or "dieseling" is caused by excessive gas in the system. This can be caused by an excessive amount of carb. (2 4-barrels on a small engine), excessive throttling (idle too high and timing too tight), or something that causes this, such as valves floating and not shutting all the way.

Make sure you are not running your idel too high even if you go below factory spec. Older engines tend to run easier.

Visually inspect the amount of gas going down the carb at idle. Floats in new carb could be too high.

If nothing visualis causing it, 're-float' your valves and see if it stops.