My 68 Chevelle idles way too high at startup. Its got a 350 in it with a stock carb. It'll drop back down if i gas it real quick, but only sometimes. If i do that on cold days the car will die.

I noticed that (I only recently found out what it was) the idle solenoid isn't connected to anything. Where am I supposed to wire that up to?

Sounds like the choke either needs to be repaired or adjusted. The fast idle problem can be adjusted to desired rpm when the choke is on but when you kick it off the car shouldn't die. Just remember fast idle should bet set at manufacture rpm. Too slow and the engine will load up when the choke is working properly. I would consult a repair manual for more info as there are many adjustments to be made as well as many styles of carbs all with their own specs. As for the solenoid if your car has a/c it may be an idle up solenoid designed to increase/maintain idle rpm when the compressor is on,in this case i believe it should be wired in the a/c clutch circuit. If it is an idle stop solenoid it should be wired to 12 volts with key on and this will be used to set base idle. At any rate a good repair manual will make this fix easy. Hope this helps....