How much spring is too much?

[Ribbedroof]

So, looking to replace the weak saggy front springs in the wagon. Armed with my old TRW coil spring catalog, I found that the OE springs (CS5600) are rated at 346lb/in. My opinion is that is too soft. Last time I put springs in one, I went with (CS5608) 420 lb/in. I've seen references to the CS5660 spring, which is rated at 639 lb/in. Then there is a spring (CS5662) with a rate of 706 lb/in.

All of these are very close in terms of load rating, and installed height.

I felt the 420 lb spring, while an improvement, was still a little soft. I would be interested to know what people have selected, and what their impressions were of the spring they selected.

 

[pontiacgp]

I have the 5660 trimmed with a rate of 660 lbs. I like it with the 34 mm hollow sway bar. It keeps the front of the car stable in a high speed corner

 

[Onehit]

I just installed the 5660's in my H/O it sits at about 25 3/4" from the center of the wheel well and made a big difference over stock. The car handles so much better now.