Question about a trans I have.

I've heard all kinds of opinions, but the only ones that matter are my customers'. Tell my why th400 and th350 have always used smooth frictions in all clutch packs. I have about a dozen TF's to put together right now. They'll all get Alto Red Eagle .061 smooth racing clutches for third gear and a Kevlar band for second. I even had one fool shifting at 8500...on the street. I have 15 smooth frictions being delivered today and 3 Kevlar bands to do 3 TF's. All for $650 for the rebuild.