Which booster goes with this master cylinder?!?

[MrArmyAnt]

I have master cylinder 2232134 NSN 2530-01-179-7589,which is an exact replacement for the master cylinder I have. However every booster I have ordered has a bolt pattern that doesn't match the firewall, what part number am I looking for?

 

[Retiredwarhorses]

What's the part number of the hydrobooster your ordering? There are 10k and 12k Boosters...the firewall is not where the problem is, it's the width of the studs for the Master cyl...they are farther apart on a 12k booster.
the 10k's are harder to find...so I would go with 12k and the squared off hydrobooster for ease of availability.
the NSN you listed is a 10.3k MC....

the correct Booster is 2530-01-179-7590

here is an easy way to tell that it's a 12k booster....the MC studs are blue.

 

[DSO_351]

The 1st generation (oval) master cylinder is becoming hard to find. Booster has black studs. If you decide to change over the the rectangular master cylinder & booster with blue studs, you'll need to change a couple brake lines too. The master cylinders have ports on opposite sides.