Water temperature sender thread on V8 carb

[lebanon]

I am buying the VDO temperature gauge for my V8 110, but I don't know which sender to order as they have different model with different threads,

1/8 NPT
M14*150
M16*150
M18*150
M10x100
1/4 18NPTF

What should I order?

[lebanon]

For future reference the thread is 5/8 18 UNF