I have tried the "Stovebolt Search" and could not find an answer.
I have what is supposed to be a 1955 2nd series 235 in my 1957. The temp sensor from my old motor does not fit the hole in the head of the "55" motor.The hole is too small.I bought a new one and it is the same size as the old one.
I tried to check the motor & head numbers to make sure the motor is really a 1955 235. I can't figure out what it is. Please help if you can. The block # to the left of the distributor is: 0512175F255X
and the head number is 3835913 GM24
If anyone can tell me so I can get the correct water temp unit I will be gratfull. thanks.

1957 Chevrolet 1/2-ton Stepside LB in the Gallery
My Photobucket shots

The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself." - John Stuart Mill (1806 - 1873)