Gary, Does your jake brake work when your cruise control is on? That might be a conflict.
Jon. My retarder works great and I've never had it higher than 228 . I can't see where replacing the trans oil sooner is any big deal. Instead of 50000 miles, replace at 25000 miles.
Kevin, how are you? How's those girls?
I wouldn't mind having both the retarder and the jake but I would not give up the trans retarder. It stops a 50k bus very quickly.