'''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!
Almost all decent bike shops have bottom bracket chasing and facing tools that will clean up the threads and assure the shell faces are flat and exactly parallel. It sounds like that is just what you need.
BTW, the tools are very expensive so individual ownership is almost unheard.