The only time I have seen an over sensitive brake pedal was when something was wrong with the brake booster. First, is it the correct booster? 1969 was the year Ford switched from Midland to Bendix. Some early 1969's still got the Midland booster. They do interchange without any modifications. From what I understand, the Midland booster provides greater power assist but was unreliable compared to the Bendix booster.
*** Before you condemn the booster, follow Mach1Rider's and Jett 445's suggestion and make certain everything is correct.