Since your problems have been present since the "rebuild" I'd get one of my rebuild kits and start over. While you are in there check the power piston height, and make sure the power piston hanger arms aren't bent, up, down, or both. Since you used someone else's kit that may be part of the root issues you are having, low quality/incorrect internals, gaskets, etc. My rebuild kits are application specific and not "generic". They come with the correct parts, and highest quality in this industry. They are also the most complete in this industry......