I have a 5.0L with a bad oil pressure sending unit. When I went to the parts store they want to sell me an oil pressure switch instead of the sending unit. What is the difference? Does it matter if I get the Switch or the sending unit?
My guess would be you need an oil pressure sending unit. An oil pressure switch is only going to turn on/off at a preset pressure, it would be used to turn on an idiot light. An oil pressure sending unit will send a variable signal that is proportional to the actual oil pressure. You need this if you have a gauge. I can get you the part # when I get home, I just had to replace mine last week. I have a 454, but they are probably the same part.