I am working on a vehicle that sat for a long time, but I dont have much vehicle history. It is a 1984 Chevyvan30. That is the Chevy Cutaway van with a box. It has the G30 engine, a 350 with a 4 Bbl Rochester carb. I am replacing the carb, all vacuum lines and any thing I suspect to be bad. I do not know what this part is, so it's hard to ask for a replacement part. Can anyone tell me what this part is please? It sits just in front of the carb and has one electrical plug and two vacuum lines. The plywood is covering the manifold while the carb is off. Thank You!

 

My guess is it probably has something to do with emissions.