Cannot find thermocouple for CTC dual extruder (Makerbot etc)

[travbowls]

I am getting the following abotu 10 seconds after start-up:

Extruder Overheat!
Software Temp limit Reached! Please
Shutdown or Restart

I’m obviuosly hoping it’s not the board, or a fried chip, but I’d like to replace the thermocouple(s) first to be sure it’s not one of those. I ordered some on Amazon, type K, but they are noticeably smaller guage wire and loop connector on the end. I cannot find the right ones anywhere.

Will these work, and what would the “upgrade” to handle higher temperature do?

K-type Thermocouple Sensor 650°c- CTC Upgrade Makerbot for 3d Printer Parts...

Thanks for any tips