I will be doing the same conversion this summer, and just like you with original ford parts. I've been told that the non-power brake pedal can be used, but it will fade closer to the floor than what a power brake pedal would. Did you change out your master cylinder as well? I know you need the M/C for power brakes. I'm not sure what the difference is, but I heard the bore is different. Also, did you replace the check valve on the booster as well. Some rebuilders don't include new ones on rebuilt boosters.
Here's a few photos of the Power brake pedal for a 66, I hope this might help some.
http://members.spree.com/entertainment/whizco/miscphotos/mvc-826s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-827s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-828s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-829s.jpg
Doug
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http://members.spree.com/entertainment/whizco/owner/dwhisenant/66tl2.jpg
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Here's a few photos of the Power brake pedal for a 66, I hope this might help some.
http://members.spree.com/entertainment/whizco/miscphotos/mvc-826s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-827s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-828s.jpg
http://members.spree.com/entertainment/whizco/miscphotos/mvc-829s.jpg
Doug
[color:red]VMF Exchange Board</font color=red>
http://members.spree.com/entertainment/whizco/owner/dwhisenant/66tl2.jpg
[color:blue]My Mustang is Camera Shy</font color=blue>/forums/images/icons/blush.gif