MANUAL BRAKES TECH NOTE: Generally a 1" bore master cylinder is best with manual disc/drum brakes. Manual brake master cylinders have a smaller piston bore diameter to maintain sufficient fluid pressure in the braking system. They also have a deeper hole for the brake pedal pushrod. TECH NOTE: You can use a manual brake cylinder on a power brake system, but not vice-versa. The power brake cylinder's larger piston bore cannot supply the required level of hydraulic pressure required by manual brakes. POWER DISC/DISC TECH NOTE: Generally for OEM disc/disc brake applications, the 1 1/8" bore is usually the way to go. POWER DISC/DRUM TECH NOTE: Generally it is best to use the 1" bore for power disc/drum applications. TECH NOTE: Use a deep hole model for manual brakes and a shallow hole model for power brakes. TECH NOTE: The above information is a general guide. With custom brake applications many variations can be used. CLICK ON THE PICTURES FOR DETAILED INFORMATION Tuff Stuff 2017NA Chrome Plated 1967-1974 Ford Power Brake Master Cylinder Tuff Stuff 2071NA 1968-1982 Corvette And Other Power Disc F Disc R 1 1/8 Bore-Shallow Hole Tuff Stuff 2018NA Power Disc F Drum R GM and Hot Rod 1" Bore-Shallow Hole Tuff Stuff 2019NA Manual Disc F Drum R GM and Hot Rod 1" Bore-Deep Hole Tuff Stuff 2023NA Polished Aluminum Disc F Drum R 1" Bore-Shallow Hole HOW TO ORDER: 1. If there is an applications box, click, then scroll the applications box to find your vehicle. 2. Click on your vehicle. 3. Click "add to cart" 4. Enter your information and submit order. 5. If there is no applications box, then just click "add to cart", then enter your information. HOURS: 11:00 am to 6:00 pm Monday - Friday Eastern Standard Time We welcome CANADIAN customers! For ordering information, click on "Orders To Canada" at the top left side of this page. We will not ship to freight forwarding - expediting companies. PAYMENT METHODS: PayPal, Visa, Mastercard, Discover, American Express, money orders.