Well, back from an unsuccessful trip to DC adjustment land!!!
After centering the detents, took 2 right turns in parking lot which produced 2 pronounced bangs and associated shakes in Ex. Straightened out to remove bars for trip back to stable, and found that either side would not release. Don't think it was totally the detents hanging up, 'cause the chain hangers would not rotate when the chains were loose. Took a few whacks with brass hammer to dislodge the bars and remove. Now I have a slight indentation in the right side frame from the snap up pinch bolt, but the snap up looks unhurt.
Parking lot is fairly flat other than drainage slope at the ends toward a flat center. The turns probably were close to a flat turn without much up or down to either of the TV or the TT during the turns. But I would bet that if I was in a compound angle turn, the head rotation may have made the binding even worse, only speculation.
FYI, I have not done any reinforcing on the frame, and maybe the new HD snap ups would not have dented the frame if used, don't know. Have to step back and think and decide what to do next. I am thinking of going back to the old welded round bar head and my 750# bars and recheck how the combo works. Maybe look for a couple of used 1K bars for the old head.
John, do you know if the cams have been changed, like maybe widened (??), since my purchase of the DC in '04??? Too late now to call Cequent out here on the left coast.