I hope you guys can help me. I'm in the process of installing a new GM crate 350 in my 83. It has the factory 305 still in place. My question is that there are a couple of sensors that I am unsure of. One is located just above the oil filter and has three wires plugged into it, the other one is located on the pass. side of the engine just behind the starter and only has one wire going to it. Can you tell me what they are for and if I am going to need them. I am removing the SMOG equipment and installing headers. Thanks for any help.