Oil Pressure Sending Plug

[lkt1954]

Can someone please tell we what size the plug for the oil pressure sending unit next to the oil filter on a 69 350?
I took mine out, set it down and now I can't find the darn thing.

Thanks

[Wrenchbender Ret]

The one behind the dist. is 1/8" pipe thread. The one by the oil filter on a big block is 1/4 pipe thread. I am not shure about that one on the small block. If you buy 1 of each you will have it covered.

George

[lkt1954]

I thought it was 1/4 not as well as, yet I cannot get a 1/4 not brass plug to start. I was able to take the original plug in and out with no problem, so I don't think it's a thread issue.

[lkt1954]

Can someone confirm this plug is a 1/4"-24npt plug?
I have tried for over an hour to get it in and I cannot.
HELP.

[Wrenchbender Ret]

Are you sure its an oil pressure outlet? All the oil sending units on sbc i have worked on are mounted on top of the block behind the distributor. Could it be a boss for a brace or something? Try a 3/8 coarse thread bolt.

George

[AussieinNC]

If you mean the threaded hole adjacent to the top of the oil filter mount area it is not an oil pressure port...it is a mounting point for the bracket for the clutch pivot ball mount. I think from memory it is a 3/8 or 7/16 UNC thread....

The hole is marked with the X in the pic attached

[lkt1954]

Thanks so much it's the on with the X.
What confused me is it had a plug in it with a allen head.

[RustyPile]

Originally Posted by lkt1954

Thanks so much it's the on with the X.
What confused me is it had a plug in it with a allen head.

If it had a plug in it, the plug was installed "aftermarket" by someone not knowing what they were doing..

[67 Burb]

Here's the oil pressure switch on my 1989 engine. I use it for a safety switch for my electric fuel pump. It turns off the pump if the engine dies. The engine was originally TBI equipped. The threaded hole seen here is the one marked with a blue X in Aussiein NC's post. The photo is actually sideways of course. Is the threaded hole for the clutch pivot if needed?

[67 twins]

Originally Posted by 67 Burb

Here's the oil pressure switch on my 1989 engine. I use it for a safety switch for my electric fuel pump. It turns off the pump if the engine dies. The engine was originally TBI equipped. The threaded hole seen here is the one marked with a blue X in Aussiein NC's post. The photo is actually sideways of course. Is the threaded hole for the clutch pivot if needed?

I don't think you are looking at that correctly. The open hole above your switch in the photo is the same as the X in the original photo.
In the original photo there is no hole where you have the sender in the second photo.

[AussieinNC]

Originally Posted by 67 twins

I don't think you are looking at that correctly. The open hole above your switch in the photo is the same as the X in the original photo.
In the original photo there is no hole where you have the sender in the second photo.

The TBI engines included a second oil pressure operated switch to shut off fuel pump if the oil pressure dropped.

As the OP posted a 69 350 engine, the threaded oil cut off switch hole should not be present.

[The Rocknrod]

Here is my latter model 350 and you can see the oil P switch in the same position. Then there is the one on the rear of the intake drivers side (not my engine).