72 Dart Struggles and Dies today, Why?

I have a hard copy of the service manual.

I replaced the cracked hose that connected the Choke Vacuum Diaphragm to the carburetor. It did not help.

I did not find a egr valve. There is fitting rising out of the back of the intake manifold, drivers side of the distributor. A small hose runs from the fitting to a black, round, "spotlight" shaped part mounted on the passenger side fender. The hose was cracked also, I replaced it and did not help.

So I replaced all of the other hoses of that same diameter. One that leads from the vacuum diaphragm to thermostat on the air cleaner. One that leads from the air cleaner thermostat to the carburetor. One that leads from the distributor vacuum chamber to a "T", from the "T" to the charcoal canister. I also replaced the connector from the air heater to the air cleaner, it was cracked.

After of that it still did not fix the problem. It runs well with the choke set. Take the choke off and it struggles and dies. Even if you press the gas peddle to keep the engine running, it runs rough with out the choke set.