Sounds like he changed to a dual master.That car had a single.If it has drums all around get one for a 67 or 68 C body with 4 wheel drum.Bench bleed it install and bleed the system.If its power brakes they just un bolt from the booster.Manual you have to unbolt the rod from the pedal and reinstall the new rubber on the old rod and seat it in the back of the laster.Rocky