ok, got a question. I did a 383 engine swap in my car. Now after swapping in the new engine the temp gauge runs from about 220* to about 265*. What's the deal? It was running normal when I took the old engine out. The sensor is brand new. I'm guessing that the block I'm using which is out of a 73' blazer might have a different temp sensor. Is that possible? Maybe the Ohms are different or something right? Oh yeah, and I replaced the thermastat too. Its a 195*.

 

Thats a stumper. Where is your old temp sending unit? I would do a quick swap with that one and reads what it says. Another possibility although highly unlikely (because it is new) is that the thermostat is sticking. I am sure you know this but take the radiator cap off before starting the motor and when its cool and make sure coolant is flowing into the radiator verfying the water pump is working properly.

 

Did you use the water pump off your old motor or the one off the '73? Because the '73 water pump is standard rotation and a serpentine belt system uses a reverse rotation water pump.

Just a thought.

 

The water pump is from the old motor. Not the 73. I think tomorrow since the water temp sensor is only 5 bucks, I'll get one for a 90. Then try them both. Only way to be sure.