the 1/2" ratchet i used a 7/16" bit and the 3/8" i used a 3/8" bit, on a side note you have to drill REAL SLOW, they drill real easy
i used the
SDD8R1RR for the 1/2" ratchet
SDD6R1RR for the 3/8" ratchet
they are just a little bit longer than the soft grip handles that came off