[Jeepwm69]

Originally Posted by lolife99

Look at this thread also:
http://67-72chevytrucks.com/vboard/s...d.php?t=209390
A lot of parts stores show JB3 or JB5 when referring to brake parts,...

QUOTE:
JB3 is the 1" thick rotors
JB5 is the 1.25" thick rotors

Thanks! Makes sense.