7.3l IDI tach thread size

[Exekiel69]

I'm drilling a hole in the cummins gear case to adapt the IDI tachometer. I need to know what size thread is it so I can buy a drill and correct tap for it. Also, if anyone know where can I buy this since the local auto parts does not have it.

Thank You.

 

[Exekiel69]

Come on guys, help Me out here. Anyone know?

 

[Exekiel69]

Well I got the drill bit and tap at grainger so I'll post pics of this when I'm done.