Originally Posted by gaucho777

^Neal, I think that's the solution for the reverse of the OPs problem. As you know, the nylon insert allows a nutted bolt to be used in place of the recessed bolt. However, sanzbajo wants to replace the nutted end with a recessed allen nut. It will likely be a problem, since the hole in the brake bridge will likely need to be enlarged to fit the recessed allen nut. Ditto the fork crown, though you can avoid having to drill out the back of the fork by mounting the nut inside the steerer behind a curved washed (I haven't done this myself). It is a fairly simple mod, though many would frown on modifying a classic frame for this purpose, and it may decrease the value if it's truly a collectible frame.