[amcmike]

If you can measure the wire diameter, overall diameter, and number of coils, the spring rate can be estimated. Then you have a starting point to figure what would give you a better ride.

And maybe you could trade with someone here?

With the large bars, you'd probably be happy with a factory spring. Even high performance factory springs were pretty liveable. So for my Firebird front springs, I went to NPD. They let me look at three different "factory replacement" springs (there are about 20 different p/n's depending on year ('67-69, engine size, and convertible vs. coupe)). All had the same wire diameter (measured with calipers) and overall diameter, just different number of coils. So I picked the least number of coils to get the stiffest/lowest. It also turned out to be the cheapest (less metal I guess) at about $60/set. I calculated the rate to be around somewhere between 375 and 400 lbs/inch for my Firebird if I remember correctly. Ride height came exactly to where I wanted it. I've done other things to the suspension, to improve handling (bars, delrin a-arm bushings, solid body mounts, lowered a-arm mounts, etc., better shocks, larger rims, wider tires, etc.), so it wasn't necessary to go super stiff and kill the ride. The low friction delrin style a-arm bushings lessen the harshness of the springs a little, also.

Like you said, our roads suck here. But with my setup I'm not afraid of small pot holes, torn up roads, railroad tracks, or pulling out of the driveway (has slopes towards the road and a rain gutter). I've even had people comment about how nice the ride is. Corners beautifully (had compliments for that too), so much that I need to upgrade the steering to really take advantage of it. Thank goodness for Herb Adams' book.