Oil pressure sending unit gone bad?
 

For background: I took the bottom of the Olds 350 apart a few months back to replace the oil pump, timing chain and gear, and oil pan gasket (along with new engine mounts). Pressure was great up untilabout 2 weeks when, according to the dash oil pressure gauge, idle psi dropped to 1 and 3000rpm netted me about 3.

Now, I know, of course, that that is incorrect since there's no valvetrain noise at all, nor am I having any temp or lubrication problems. That being said, I figure the oil pressure sending unit is faulty.

If so, what part number do I need? Half of the ones on Rockauto say they're for vehicles with a 60psi gauge, but if you look at the product detail, they're actually for warning light vehicles. What gives?

Re: Oil pressure sending unit gone bad?
 

This is what I found when I catalogued your truck at a Rockauto. A good rule of thumb is the little skinny ones are for lights and the big bell shaped ones are for gauges.

Looks like there are several "with gauge" ones to choose from. I took a screenshot of them. Note I didn't include any of the ones for "light" applications in this picture. They look much different.

Re: Oil pressure sending unit gone bad?
 

I always wondered about something. What's the difference in the Delco D8032 & D1829 which says Rally Ga (z53) . There both the Big fat ones.