Camaro clip, need stiffer springs

Has anyone put stiffer springs in their camaro clips?
I put a camaro clip in my 66 Merc crew cab and I could use a little stiffer spring.
The stock ones were sacked out a bit.
I haven't thrown the truck on race car scales yet to see how much weight is on each corner.
Thought about putting 75 Impala coils in it since we have a set sitting around.
So has anyone substituted another set from another car before? Maybe even chevy 1/2 ton springs?
I've looked around for different rates of stock springs but can't find frick all!
Thanx guys!

-Shiny

 

you can buy new big block springs.

 

I used 2" dropped uprated springs (think they are 480lb?) which I got from Summit on my clipped 56pu. Very reasonably priced from memory, or try one of the Camaro houses, they seem to have the same stuff in stock.

P.

 

Springs and Things... http://www.espo.com/

 

I have a Camaro Clip in my '60.

The ride was a little too soft.

So I put Pontiac T/A Big Block springs in it.
( about $80 at the local parts store, if I remember correctly )

They did not raise the ride height, and the Truck no longer bottomed out over large bumps, and uneven intersections...