Pretty much the title says it all....

I am mainly interested on the shocks/springs. Anybody knows this?

TIA,
Carlos

no

u mean the MS shocks & springs are interchangeable between the two cars????

Yes.

A friend with a 2005 Mazdaspeed Miata changed his suspension to JIC and he is selling the MS suspension now.

I already have the MS sway bars, strut bars... Just need shocks and springs.

Thanks,
Carlos

they're softer than the OE RX-8 parts

I cross referenced the part numbers for Eibach, H&R, and KONI and none of the part numbers matched between the two vehicle for spring or shocks. It is possible the shock bodies are the same but the valve rates are different (whether softer or harder). If the valve rate is softer this can cause the vehicles suspension to bottom out and possibly damage the shock and other suspension components.