door jamb switch

[roadrunner440]

im in desperate need of two door jamb switches one is a dual pade type and the other is a bullet conector type the only prob im running in to is the treads are 1/2 " thick and seems like impossible to find new if any one has any of these used all ive been able to find is the 3/8 ones and parts store show only the 3/8 ones are these the corect type of a 73 rr plz let me know thanks pat