subframe coil spring rate - HELP!

[hotrodsbyray]

have 57 short step side. putting 81 trans am subframe. wheel base not changed. 95 chevy 4.3 liter vortec tbi engine with 4l60e trans in stock trans am location. putting qa-1 coil spring kit in rather than original coil spring. they have several coil spring rates - 250, 300, 400, 600, etc. how do you know which one to use?
anybody can help me?

[dwcsr]

this should help
http://www.qa1.net/pdf_files/street_rods.pdf
I think your going to be at 250

[hotrodsbyray]

thanks for the reference. on their weight reference chart, the only truck they have listed is a 48 chevy with small block v-8 at 1950 pounds front and 1450 pounds on the rear.
they recommend 350 # springs for front weight 1701 - 1900 # and
450# springs for 1901 - 2100 #.
i thought 250 # springs would be correct also but their charts indicate otherwise.
i guess having a 4.3 v-6 rather than a v-8 would put a little less weight on the front, putting it in their 350 # category.
any of you subframe guys ever check front - rear weights?
anybody with coilovers that can tell me about their ride?

[entourageguy]

I have a MII front end. Just checked and it came with 400# blue/red. Ride is not too bad.

Brian ..

[hotrodsbyray]

brian,
thanks, that's the kind of info i am looking for.
anybody else?

[1-ton of fun]

no real weight info, but i am going to run pretty stiff coils. i think mine are about 650 lb./in.

all iron sbc, th350, in a 3/4 ton 59

i have 1000 lb./in. coils in my DD truck (ford lightning) which works out to a wheel rate of about 588 lb./in. (with a motion ratio of 1.7) it handles great, holds its own on road courses against mustangs. the ride is a bit stiff, but i don't mind because of the handling improvement. that truck weighs around 4800 lbs.

the nova clip has a higher ratio, so wheel rates would be lower.