Another place a threaded plug might be appropriate instead of a drift pin would be the full flow- - - -bypass selector pin on a late model 261 stovebolt engine block. I'm probably going to thread that hole when I build up one of the two late production 261s I have.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!