My '75 Scamp 383 Build

Well it's been a while since I've posted an update. I pulled all the block plugs, picked up a 3/8 drive 5/16 square head socket for the oil galley plugs, and gave the block her first bath! After a spray down with Gunk, I used LOTS of Dawn soap and connected my hose to the hot water line. Moroso Engine Brush Kit is a POS! It went back to Summit. My rifle cleaning brushes are MUCH better.
The crankshaft needs just a couple journals gone over again with 2500 grit wet/dry for a polish - pretty close to done.
Cleaned up water pump housing and had to go to war with one of the heater hose fittings. Wow, what a *****!
I boogered it a bit, and I need your opinions on whether this will seal with a 3/4 NPT plug.
Here she is with a cleanup/paint job and the new reproduction neck I picked up at Carlisle.
WP housing 1.JPG
and a couple pics of the threaded hole in question:
WP housing 2.JPG
WP housing 3.JPG
As you can see, I ended up cutting deeper than I should have when I got that ***** out one chunk at a time! I can screw in a 3/4" NPT plug, but will it seal with tape?