In case anyone is wondering what sender fits these thinwall engines and works with the factory gauge head , NAPA's # TS6469SB and it comes with a new wire end and plastic sheath too . This one is a BIG ol' thread and won't fit earlier engines , sorry . FWIW , YMMV , etcetera.....
Charles, I have had such bad luck with the gas type sender that I wanted to go with an electronic sender. Nate suggested a 59' 235 water temp sender which is 12volts. I got a GMC cast water/hose fitting which bolted right on my 216's collar and I believe our host sells a electronic original type gauge. I used another local gauge rebuilder for mine. The sender cost $7.95 @ NAPA. She had two on the shelf. My rebuilder said they weren't to be had for any money. Go Figure!
Temp. Gauges & Senders You cannot use this one in a 216/235/261 engine because it too big so no adapter will work . Technically , what you use to fit a newer , smaller sender into the older cylinder head is called a " Bushing " but let's not quibble . I , personally , always prefer the Bourdon Tube types of gauges , be it oil or temperature but this '76 I have , has an electric gauge head in the dash so I made it work as original . Whenever someone says ' not to be had , period ' that just means : you're not looking hard enough or in the right place .
