Rich,
I do not - actually, when I had this done it was because I had a leaky black tank valve since I picked up my trailer. No matter what they did to adjust the cable, it wouldn't work. I asked the service department (Jason) if he would be willing to put an electric valve in when they were changing it out. He said they were actually looking into it and they would. Turned out, there was something stuck (plastic) in the valve gate when they took it out. Looked like a manufacturer's defect.
I love the electric valve and asked about the gray tank as well. There is actually not enough room where the gray valve is to install the electric version and it is right on the other side of the handle so, there is not much chance of it stretching. So, I have one of each. Only trailer in the fleet configured like this. It has never leaked since.
Cheers,
Brian