Quick query

[mikenash]

Hi Guys

I'm thinking that next time I'm up at the site where my Listers are I need to clean up the threads in the case where the four big cylinder/head studs go one one of my CSs

I'm just ratting through the box of taps & dies in my work truck - but I'm 400Ks away from the engine to check out thread and details - but I figure someone will know:

Are they 3/4 UNC?  And do the threaded stud holes go all the way through into the inside of the case (as in - do I need a bottoming tap?  or will any old tap do?)

Cheers, Mike