I'm running a gbs zero with a zx9 engine after the swap from the pinto I had to lower the ride night due to the weight difference that that lifting up the nose. Because if the springs are now not working correctly as when lifted off the floor the loose contact with the retainers and are loose. What springs are people using ?
For what I understand your shock extended length is more than your springs can handle.
I think you need longer springs.
Or maybe limit travel with an extension strap or stop.
HTH