I did quite a bit of research on this and found the screw threads are indeed 12-24 as is the heli coil kit.
The drill size used is just a bit larger than the original threads, so I am pretty comfortable with the whole setup being the right setup.
Thanks guys.
Rusty, I kinda like the old school style washers as well.
I have a Holley Trick Kit that I can check for those.