Lots to think about jcc, and since we will never have a late B on a shaker or any other scientific measuring device, this whole exercise is "best guess", and that's why I came here to ask folks for their thinking on this. So thank you for yours.

The late B, starting in '73, is sort of an odd duck because the upper control arm mount moves to an extension of the K-member, not a welded part of the inner fender and uni-body like on my '72 Charger or '70 Duster. Like the earlier cars, that K is bolted solidly (or will be) to the body. Is the K helping the body not flex, or is the body helping the K not flex, or a little bot of both?

If the K tries to flex, then it will have to flex the body it's bolted to. If that's the case, and if you picture the body with the K removed, then that core support becomes the only substantial cross-member in the body structure between the the torsion bar cross-member and the bumper. And I would "guess" therefore that it provides a meaningful function on controlling body flex. It's an interesting argument, as WITH the K in place, the K becomes by far the most substantial body cross-member, being dual purpose in that regard.

I think in a more max effort car, with bigger, stickier rubber, it might be worth the effort. But my guess is that for my application, it's not worth the weight or the trouble. But that's why I wanted to hear what other thought.