I too wanted differential braking on my 4010 HST. While looking through the service manual I also saw that there are differential brakes on other CK models and wondered if I could order those parts and convert mine over. I'm guessing there is not room on the right for both brake pedals, but a single left side pedal seems like a good plan. I have certainly had some situations, mostly connecting implements, where the split second between the go pedal and the brake allowed a slight roll back. While I like the idea of differential braking, I can't say I've ever actually needed it. Left side brake though, hmmmm, guess I'll be heading back to the parts listings to think this over some more...