1979 Dodge Truck Carburetor Problems

I have a 1979 American Clipper Motor Home with a 350 4 barrel. The choke seems to not engaging when I start ti. It will stall and finally start but with a very rough idle until it warms up, then when I give it gas it sputters before it takes off. Once I get going the choke seems to engage but then it won't release. Should I replace the entire carburetor or is there something else I can do? I tried carberator cleaner but it didn't seem to help at all.
Thanks for any help.