i just stopped short of doing that on my last rebuild. i kind of toyed with the idea. i just settled for a comp 3 angle valve job. i want to try milling it out myself on the next one i do. i don't know, that would be a lot of work for my mill. does he just do the three bosses in the intake ports? i for one would feel better about the tapped plugs than freeze plugs. i think you would have to do a lot of other work as well like higher lift cam, bump up compression, plan out induction to get a real improvement with boss removal. was he installing bolt in lump ports as well. a guy from inliners international sells them on ebay. i want to try his on my next rebuild. that would def be way to go if removing the bosses. well good luck and let me know how it works. hr