I do recall that spring……or should I say the absence of the spring. Many fell out/off. If you are looking to install one to configure for “stock accuracy” you will have to continue with an APB across the Ford empire. I do not know of any. However, if it is a matter of function. You don’t need it or shouldn’t need it. Slave cylinders had a light spring to keep the push rod “loaded”. You can safety wire it in place if concerned about losing the rod. I know, I know, it’s a MacGyver thing. TT