Wilwood's 78 or 1516 bore Tandem Aluminum Master Cylinders available in 3 finishes, plain, ball burnished, and black e - coat. These master cylinders are designed primarily for manual applications and include a pushrod. They're designed for mount flanges from 3.22 to 3.40, common measurements for most domestic cars and trucks from the mid 1960s to present, and offer fluid outlet ports on both sides of the bore. The stroke is set at 1.10 with a volume ratio of 21 between the primary and secondary chambers. Machined from high - pressure die castings, each master cylinder weighs only 3lbs, a 75 weight savings over most cast iron OE type master cylinders. We also offer a combination proportioning valve kit, which includes brackets and stainless lines specifically for use with this master cylinder, see PN 260 - 13190, or 220 - 13189 for retrofit kit.