How much weight gain from adding a Dana and roll cage.

justinp61 said
Aftermarket support is part of it. You can bet if the demand for Dana parts was equal to the 9" stuff there would equal parts available. These guys are chasing numbers, if the Dana gave them an advantage, that's what they'd be running. That alone tells me that the higher friction of the 9" doesn't equate to slower et's on the track.

I doubt that. Gear selection is one issue. The other is the copy cat fallacy. That’s when guys buy a 9 or use an 8.75 because they are going to have 2 or 3 third members and they are going to change them out. Almost never happens.