The carbs on our trucks are not electronic. Everyone thinks they are because of the dual capacity pump. This is the wire that goes to the temp sensor in the thermostat housing.
You can swap on an older carb and it will work the same as it does on older trucks, as long as the linkage works. All the dual capacity pump does is when the engine is cold, it lets the pump double the capacity of fuel. When the engine reaches about a 160 degrees it closes the valve in the bottom of the carb and then acts just like a regular accelerator pump.
I have swapped out mine for an Edelbrock #1904 q-jet.
Hope this helps,
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Mike
1985 Chevy C-10
Mike's 73-87 Chevy Pickup Site
[This message has been edited by swervin ervin (edited 11-12-2000).]