I have a 1994 blazer full size with a used 350 just recently replacing my old one. It runs good. just not all the time. I can not find the wire lead and adjoining pigtail connecter that goes to my oxygen sensor at the exhaust manifold. The o2 sensor i just replaced as the old one was busted off in the manifold and no sign of the other end to connect it to. My friend has a 93 silverado and the wiring harness looks identical to mine, so I noticed where his o2 lead wire comes out of the wiring harness and looked on mine to see if i could locate it. To no avail as I stripped the protective wrapping off that whole section of wires. i dont want to strip the whole harness looking for a broken/open wire so....and I just know this would take care of my run-ability issues. thanks in advance, Eddie