The pipe nipple method got me all the way to about 2.5 threads left, which is still pretty far away. After the 7th try of not getting further I gave up.
Today during lunch I went to Harbor Freight to get a tap. They didn't have individual taps so I just got the whole big SAE set, thinking I needed 3/4. Everything I have read says it is 3/4. The anode rod coming tomorrow is 3/4. Low and behold I go out to tap 10 min ago and it is one freakin' inch! Was that the drain hole size back in 2005?
Not sure why I didn't measure it as an estimate but 3/4 seemed about right. It is not even close. Luckily the tap set I got goes up to 1 inch so I am headed back out to tap it and also die the old rod straight since the new one coming tomorrow won't fit. Maybe I can get a 3/4 to 1 inch adapter to still use it.
Thanks guys. Any other advice keep it coming.