430 lbs Spring rate to high?

[Pyramid]

I have a 88 dodge omni. Front is lowered on a 1g neon struts (Shorter strut, oem neon springs. )
Now i ordered my sleeves n everything.
The oem spring rate is 90lbs.. But i ordered GC180.64.75 (7/2.5"/430 lbs) springs for the rear... Are these to high? My front is stiffer than before but i like it..

[Oh Damn, it's Sam]

Knowing zero about the Omni, three things to consider. 1. So long as your system is adequately damped, you're good from a suspension control standpoint. 2. You might want to keep in mind the kind of forces a spring nearly 5x as stiff is going to put on your spring mounts. A soft spring does a good job absorbing shocks and transmitting force gently, which will no longer be the case. I know guys who run crazy spring rates on coilovers on the W124 chassis are beginning to see strut towers cracking, so just keep an eye on it, and finally, 3. a lot of the "feel" of a suspension comes from how stiff the rear is. It may wind up feeling pretty brutal, but whether that's alright or not boils down to your tolerance level.

EDIT: One other thing. Stiffer rear springs are going to push the car toward more oversteer. Knowing how well Mopar products tend to handle in general, this probably isn't a terrible thing, but keep it in mind.

[Pyramid]

Well its not going to be my track car. just my daily driver.

[Oh Damn, it's Sam]

Might be a wee stiff on that light of a car then, but I'm a puss about stiff suspension.

It also depends on the motion ratio of the suspension. Springs far inboard on the suspension can be a lot stiffer and not grind your kidneys into a pulp.