The Stovebolt Site Forums The Shop Area The Electrical Bay What temp sending unit will work on 55 235 engine?

I have a 55 chevy truck with a 235 that is using the mechanical temp sending unit and guage. The kind that uses a copper tube that goes to the block. I decided to swap out the mechanical unit for a electrical unit and guage. I picked up original electrical temp guage that came out of a 57 truck. Has anyone else done this? And what kind of electrical temp sending unit did you use that will fit the block in place of the old mechanical unit? Thanks for any help

well shucks, it's easy to go the other way, (put the mechanical sender in a later head), all's you need is an adapter you can get at NAPA. Outside of drilling out the existing hole and tapping it to the proper threads, or changing to a later head, I'm not sure how you would do this.

Hang in there, hopefully someone has an easy solution.

thanks for the help, but I was wondering what electricla sending unit would work with a original electrical temp guage

OEM replacement sending units should still be available, and nos/nors sending units pop up from time to time at the swaps. However, the issue here is that there isn't an electric sending unit that will work with a '55 head, as they all used the mechanical temp gauge. You'll either need to drill the temp sender hole out to the proper size or swap to the '56 or later head to make it work.
Just out of curiosity, is there a reason you want to change to the electric gauge?

thanks for the info longbox55.I didn't realize that there would be a difference in a 55 235 head and a 56. The reason I was wanting to swap to a electric unit is because the original one went bad, all the gas came out of the tube. I then picked up a original supposedly working one that did not work. So I figured why not go to a electrical type of unit. The electrical ones seem to be more duarable then the tube type and don't cost as much.

What about a GMC water neck with the electrical sending unit in it? Wouldn't have to mess with the head?

where could i pick one up at? And thanks for the information

If you want to stay original, there are rebuilders that can rehab your old gauge. Not sure about the cost, but it's done pretty often on restoration jobs.
Jerry

would you happen to know anyone that does restoration on these guages? thanks

You could take the electrical meter down to a Stewart Warner distributor. They make bunches of senders and may be able to do a cross index for you.

YOu could also check to see that the electrical meter is working. At a guess I would use 100 ohm resistor. Hook it up and see if you get response. Do on a bench and use a 1 amp fuse just to ensure you dont burn stuff up and test for ONE second.

Dan Bentler

GMC waternecks are not common but come up on eBay fairly regular I think I have a picture somewhere of it I will look.

great, thanks