360 won't idle smooth...can't figure why

I think you could have a few issues at this point. Check the coolant temp sensor that the ecm reads reads, not the one for the gauge. See if it corresponds with the temp gauge. You will need some sort of scanner to monitor it or remove it and ohm it out. It may be bad and running the motor full rich. Also I wouldn't rule out the 02 sensor, its a good possibility i could be bad as well.