water pump and paint question

[rddaves54]

The only water pump I can find has a plug in the top of it and the old one did not have this additional plug. Is there a place a water pump can be ordered that is like my old one within reason on cost? 72 Chevy 350V8

I was also wondering about the plug that controls the evaporative emissions control system canister because I am not putting it back on. When removing the evaporative emissions control system canister I have to remove all the vacuum lines and plug the gas line that went to the tank but I am not sure what to do with the electrical wire that plugs in on the right side of carburetor. Picture shows the solenoid I am taking about.

I am going to try my hand at using a gravity fed paint gun today using primer and want to know what the best material to clean the gun with would be. I am new and starting with the bed and with primer to see if and how it is and if I can do it.