Don, I always replace the springs with springs a bit stronger. I have done a lot of work getting this right. Rule of thumb with rigid cat is to look for a spark. If you see one, you need more tension on the pan. I run 1 1/8 to 1 1/4 inch over the railhead to the wire and have perfect contact. Shown is a pan I just sprung. I will pull the springs and put them in gun bluing overnight.
Care must be taken so you can still have the operating pans work. You will have to experiment to get it right. The MTH operating pans first showed up on the 5V GG-1. I have converted all those boards but the pan motor/gearbox is a winner. A well built and well designed system.
