the recommendation for drilling is to use an R drill bit,hard to find ,will 11/32 bit do the job just making sure.

Here is a bit chart. So a 21/64 would be the closest bit to a R.

I have always used a 21/64 with good luck.

Heck I've got a 5/16" bit zipped tied to a 1/8" NPT pipe tap ready for pyrometer work.

Thanks guys,I guess they're pretty picky with the letter R drill bit which is almost impossible to find.