64-78 Brake Master Chrome 1' Bore Flat Top 9/16 & 1/2 Ports on Both Sides & Blanks For The ones You Don't Use

All Ford Masters with 60/40 Split The Larger Reservoir 60% Is for The Front Brakes and is To The Rear 

of The Master (Booster Side Rear of Vehicle)

All GM Masters With 50/50 Split Are The Opposite Way Round The Rear of Master (Booster End Rear of Vehicle is Rear Brakes usually 9/16 Port & 1/2 Port Front of Master Goes To Front Brakes Via T or Distribution Block

Depending on the master cylinder, you purchased make sure you get it right