so i found this:
BRAKE SYSTEM,PWR MED DUTY
JB1 76 88 BRAKE SYSTEM,MAN DISC/DRUM
JB2 76 81 BRAKE SYSTEM,DISC/DRUM
JB3 76 88 BRAKE SYSTEM,VAC PWR DISC/DRUM
JB5 76 88 BRAKE SYSTEM,VAC PWR DISC/DRUM
J86 76 88 BRAKE SYSTEM,VAC PWR DISC/DRUM
JB7 76 88 BRAKE SYSTEM,VAC PWR DISC/DRUM
JB8 76 88 BRAKE SYSTEM,HYD PWR DISC/DRUM
JC4 82 87 BRAKE,FRT VENTED ROTOR
JD3 76 87 BRAKE SYSTEM,VAC PWR DISC/DRUM
JD5 76 88 BRAKE SYSTEM,PWR DISC
and that leads me to believe that the code specifies power or manual, hydraulic or vacuum, and disc/drum or disc/disc.
my assumption is the booster and (especially) master cylinder my differ for different brake codes that pertain to different codes / levels of braking (i.e light, medium, heavy duty).
I have noticed a difference in master cylinder bore size from 36mm to 40mm depending on coding.
Any brake Guru's shed some light on this for me?
My direction right now is to go with a JD5 code as it was originally spec'd as 4 wheel disc (which is what i want, thus corresponding parts should work well enough in the realm of my build).
thoughts?