Jim's measurement of 2 3/8" is what I've seen on 99% of the Firebird hubs. 2 11/16" is what my taller hubs measure and they came off a Tempest. I'm changing out my factory discs for 12" rotors and wanted these taller hubs to keep the track width the same. Factory discs give our cars and extra 3/8"+ of track width per side.
Andy: Take a look at the S10 rear disc brake swap.
