I'm finishing a carb conversion that the previous owner of my '89 Camaro started on a 350TBI engine he swapped in, and am trying to figure out what to do about an oil pressure switch/sender. Should I use the original two wire plastic one that screws into the side of the block by the oil filter and just use the tan wire, or can I use the older bulb style one wire metal sender that screws in next to the distributor (and use the tan wire in the harness with an appropriate connector)? Personally I like the idea of having the metal sender next to the distributor because the plastic one, its connector and wire ends up being right next to the heat of the left header where it's mounted, which doesn't seem like a good idea to me..

 

You may need both.

The "bulb" one by the dist works the gauge if it's a one-wire. The other may be involved with the fuel pump.

 

I'm running a mechanical fuel pump. I'm just wondering if the dash gauge can interpret the older bulb style sender signal the same way like it interprets the signal from the newer 1989 sender.

Was the oil pressure gauge the same between the earlier 3rd gens that used the metal sender and the newer ones that used the plastic one?

 

My car is tbi to carb and have it with the metal sending unit by distributor single male connection. Its a brass tube up from block with elbow and then sender with the tan wire connected

 

What's the brass tube for? I know the early oil pressure gauges had a copper tube running from a sender on the engine to the gauge in the dash, but that type of oil pressure gauge was done away with decades ago.

I'm thinking the second wire on the original two wire sender that goes to the ecm is so the ecm can shut off the electric fuel pump if there isn't any oil pressure for safety reasons and to save the engine from damage. Since I'm running a mechanical fuel pump that shouldn't be necessary.

 

Raises the sending unit so it can clear the intake. It's just a plumbing fitting like you can buy at the hardware store.

 

Like mentioned above it raises sender above intake for mounting it pending intake manifold it would have 90° fitting then sender. Ive used a 45° fitting before also and think it works better depending on your intake and vehicle applications.
I'll post a picture tomorrow if that helps