Rear lower control arms NA/NB

[greenMachine]

Has anyone got a picture of these, showing the difference ?
Been advised the only difference between the two is "Sway bar mount with NB has a larger single mounting tab" and trying to figure out how that will affect me, if at all for using one in an NA...

AFAIK, the rears are identical. The fronts have the different ARB mounts, with the earlier 'U' mount preferred as it is stronger, and less likely to fail with heavier front bar.

[Hellmun]

Stolen from the goodwin racing site.

A design change to the front lower control arm sway bar attachment points on the 1999 Miata chassis results in significant flexing of the lower control arm sway bar end link attachment bracket under hard cornering, possibly leading to premature failure of the bracket. The 90-97 Miata was designed with a U shaped end link attachment bracket on the lower control arm (LCA). The 1999 Miata was designed with an L shaped LCA attachment bracket.

Unfortunately, we do not believe that this L shaped bracket design will be adequate to handle the demands of a stiffer aftermarket sway bar. To remedy this shortcoming of the stock LCA bracket assemblies, we strongly recommend installation of the Lower Control Arm Reinforcement Flange Kit (Part No. 54111). While a minor welding effort is involved to install these reinforcement flanges, the benefits are worth the effort. After installation of these flanges, the stock end links cannot be reused.