The SL alone had three different fuel tanks. A sender for the 72 and 73 are specific to their fuel tanks, and later year senders will not work on the earlier cars. MaKe sure you match the fuel sender to the serial number. Not sure about the SLC's, but I am sure they follow the same logic. Match the numbers.
I do know that the fuel senders are prone to failure and can be removed and cleaned up and often will work good as new. I have the instructions to clean and test them if you would like them.
Email me at
engr693@yahoo.com and I will send you what I have.