trouble bleeding brakes on 66 after replacing lines and changing to duel Master cyl

[JrJc66]

I replaced all the brake lines and hoses as well as switched out the single master cylinder to a duel master cylinder. Well I had no trouble bleeding out the rear brakes but the fronts are a different story. Brake peddle will only go half way to the floor even with a front bleeder open. The fluid in the reservoir has not moved at all. What could be causing this? Could the front wheel cylinders be bad? As a quick background, I bought the truck last summer with a broken brake line which is why I decided to do the duel MS swap. I have yet to have the truck on the road. Supposedly all brake parts within the drums are newer. I haven't taken any drums off the verify. Any help or hints would be greatly appreciated. Thanks