restoring 53' cadillac 62 series and im new here need advise!

hello everyone, i have a 53 cadillac 62 series 4 door. im rebuilding the motor and there is some kind of part i cant identify. it was laying up on top of the motor, its a round little donut thing with a spring around it (about the size of a half dollar). 90 degree metal bracket and a ground and a positive wire. no idea what it could be so any help would be great! i dont know if it is something that i can do without or if it is a must to run he motor. thanks!

 

Welcome from South Ga >>> any pictures of the part you wish to id?

 

Welcome to the hamb from wi

 

Welcome from Es*** Illinois.

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