rsnyderjr2

Hi Guys - prepping my GM crate engine to drop into my '81 - I have a couple sensors (shown below - that go on each side of the block by exhaust mani's) that the hole sizes on the new block are TOO BIG for...

1. What are these sensors for? (oil and coolant temps perhaps?)

2. Any suggestions on what kind / size adapter(s) to use?

Many thanks for any help here!!!

Rich

AzMotorhead

If they are both in the head, then they are coolant temp.
One is probably for the guage and the other is probably for the computer.
Just go to your local ACE hardware and get some brass bushings to adapt them up in size

rsnyderjr2

Cool - thanks AZM!!

Rich

Sigforty

The right one with the single prong is your temp sensor. It is 1/2 npt. If you have enough wiring to stretch you could just relocate it to the intake manifold. They should have a 1/2 npt port. I am not sure about the other one, but it looks like someone was just using it as a plug. Unless the 81 had another temp sensor for something like tcs.

The new crate engine probably had 3/8 npt ports. That is why they do not fit. You can possibly try a 1/2 to 3/8 reducer if you want to keep them in the head.

4SPDL81

I think the one on the left in your pic is for the electric fan ( mounts on the right rear) ...Good Luck!

BKarol

Think this might be why Willcox came up one that will be a replacement with 3/8".: https://willcoxcorvette.com/corvette...79-3-8-npt-new

rsnyderjr2

Very helpful - thanks guys!!

Rich