I have the '93 S10 Blazer 4.3 (W) engine that is having a major shutdown problem. I think it's the Oil Pressure Switch telling the ECM to go take a hike. Looking at Rock Auto I see there are two different switches. One with coarse thread and another, with fine thead....thanks GM... Would be nice to have the new switch in hand, when I have to tear the entire top off to get to it, but don't know which thread it is. Doing a search on this, Swarlkk you said it's coming off a stand pipe doing a 90 facing towards the booster. This is not the case with mine. It's comming directly out of the block and the connector and sending unit is facing directly at the passenger seat. Maybe the stand pipe application requires the coarse thread and the one into the block uses the fine thread....don't know any info on this to prevent me from having to tear the whole thing apart just too find what thread it is, would be greatly appreciated....thanks!!