If you look at your existing carburator, does it have an electrical wire hooked up to a little diaphram looking thing right near the choke lever? If it does, you probably have an electric choke. I'm not sure what the rules are if you have to stay smog legal, but you want to be careful what you change. The type of choke isn't like to be a problem if it's not listed on the smog sticker in your engine compartment.
This carb uses a heat operated choke (like most earlier trucks). There should be a little rod that goes down in to a tiny metal shroud right below it where it's screwed onto the intake manifold.
If needed, the edelbrock performer RPM manifold (I think it's 2101 for 1986 and earlier) have a little plate that bolts to the intake manifold for heat operated chokes, and I'll even throw in the choke element.