Thanks guys. Just wanted to confirm my thoughts before I ordered some. Well my connector is going through a quarter, so no, there's not a lot of meat there. But then again I have very little room to begin with that is why I'm thinking of threads.
Although the single quarter can be used with several of the "adapters", a double stack is stronger.
Most of the threaded adapters don't have threads all the way up and one washer thickness doesn't hold very well.
Remove the center contact and the insulator and press in the adapter.
The 801 to 510 is one meaty sucker. If room in the mod is critical then you can shorten the shell of the adapter to expose the center contact for direct contact.
Without the insulator in place you can also solder the adapter in the quarter. Remove the chrome plating in the area to be soldered first.
The epoxy on the inside is just for insulation, not strength.
The 401 to 510 is another adapter easy to use.
Rocketman