1. OEM Part Number:
8" Dual Zinc brake booster with Bail Top Master Cylinder
The master cylinder features a 1" bore and the ports measure 9/16" and 1/2".
This master cylinder will work with any drum/drum, disc/drum, or disc/disc setup.
This kit is for the Disc/Drum applications only.
2. Will Fit Following Models:

Replacement for Chevy Bel Air 1955-1957
Replacement for Chevy Nomad 1955-1957
Replacement for Chevy One-Fifty Series 1955-1957
Replacement for Chevy Two-Ten Series 1955-1957