troubleshooting power brakes

[thisolechevy]

I just installed power brakes onto my '69 K-10 and they work GREAT!! It was really easy! just unbolted the non-power, and then bolted on the power. Easy! Anyways I am having problems with the brake pedal returning all of the way up, it sits down a little and is applying a little pressure to the brakes, I can just pull it up and its fine, but then apply the brakes again and doesnt return all of the way. It has a return spring but is from the old non-power brakes is there a difference in springs? it worked fine before. I also have not bled the brakes since the swap, I have no need to as of now they work fine and do not feel spongy at all, and the truck stops QUICK. Any suggestions?
Brad