I've got a 1975 280z with a stock suspension. This is the only Z I've ever driven so I can't really compare it to anything but I feel like the ride is pretty rough. I can feel every tiny imperfection in the road and if I hit any kind of hole or bump at a good speed it feels pretty bad. It gets very floaty on the freeway. I've got it on 215/55r16 tires.
I don't race it or anything so it's just for normal street driving. I looked around at a bunch of other forums and from what I read it looks like Eibach Pro Spring Kits rated at 150lb in the front and 175lb in the rear is what people are s