I am installing these in lieu of hardening and threading the wing holding blocks. The insert package does not specify the size of drill to use, so I eye-balled it. The question I have is (and I realize this is subjective and hard to explain over email), but how much force should be required to screw these inserts in place?

I used epoxy around the inserts and screwed them in place, but somehow I felt that it didn't require a lot of force to do so, and I am afraid I may have drilled the holes a little too large. Any thoughts?

I think your talking about blind nuts? right? if you are, they just need to be set in to where the "teeth" are set into the block there mounted on. they will be flush with the block.

Not blind nuts, these are the ones I am talking about:

http://www3.towerhobbies.com/cgi-bin...?&I=LXE068&P=7

I have used the inserts a number of times. I usually drill, tap and harder the wood first then if something happens to the threads in the wood I go to the inserts. If they go in too hard you can crack the wood. I measure the insert itself then use a drill bit just over sized of that. You want the brass threads to cut into the wood when you screw them in. These are one of the places I also use Gorilla Glue, it expands and fills in any gap between wood and brass, I have had the epoxy break loose. If they start to back out just remove them and give the Gorilla Glue a shot.

Gorilla Glue is a great idea, I didn't think about it at the time. Next time...