71 nova 350 rough running

okay, so i pulled the motor to replace the rear main seal, plugs, oil pan gasket, and changed the oil while it was out. the engine went back in smoothly, but now the engine will stahl unless i stay on the gas, when i pulled the plugs, there covered in carbon or some other black soot, and at mid range rpm there is a knock under the cab.... edelbrock 650 electric choke, sb 350, turbo 350, out of comission... please help

Make sure the 12V supply to the choke is still working. It sounds, based on your descrition, like the choke might be "hanging".

Did you remove the valve covers and mess with the rockers at all? Got all your vacuum lines correctly attached? Has the firing order been checked and rechecked? Did you remove the distributor in the process?

More detail would prove to be very helpful.

Jim

thanks man, i checked and the power wire to the choke was bad, i replaced it and now there is no problem starting and running at idle, but when i drive or rev the engine it sounds like its missing a little and backfires through the carb, it gets so bad something starts to knock under the car, but thanks for the advice

That sounds like a couple of plug wires might be "switched". Check your firing order closely. The "knocking' you hear under the car could just be fuel in the exhaust igniting.

Jim