Difference between Na and Nb suspension?

Hi all

As the title suggests, I’m after knowing what the difference is between the coilies. I’m not talking about spring rates etc, I’m talking why Nb’s won’t fit an Na. Is it the thread length / shape / size for top mount, length of damper, total length of unit? I know you have to have different top mounts by the way, I want to know why…

I’m guessing no one has actually done a side by side comparison as I’ve done a search on here and nothing came up.

Cheers

 I have just (well, in the process of) converted my NA to NB Rokkor suspension. The main difference is to be found at the top where the top of the unit enters the underside of the suspension housing, and on the top, where there is an extra rubber doughnut. I will try to take pictures of NA and NB next to each other for your reference. You also have to fit new top-mounts which can be tricky to get hold of. I had to get mine on back order from Mazda, new ones not being much more than 2nd hand ones i found.

I hope this helps, i’m sure someone with more technical knowledge will add to this.

Ta ta, Mark.

Brilliant, the pics should really help. Thanks for this