[Tom Goldman]

I just freshened up an old Comp Elim trans that I did 20 years ago with a lightened stock drum .
Guy sold it to a bracket racer with a SBC that turns 8800 rpm, this thing has probably well over a thousand runs with no problem.
As Adger said , the lightning is done by plunge milling the front face of the drum. ....I've seen many of them done this way , and never saw a problem with one.