Stiffer springs for a C-10?

[Pillow]

I am wondering if there is a stiffer spring kit available for the C-10 trucks with the trailing arm rearends.

They ride like a Cadillac, but are a bit soft for a work beast.

I *think* the C-20s came with a leaf spring rear?

I am planning on buying another C-10 or C-20 for a work truck but need something closer to a 3/4 ton capacity. Just wondering if the C-10 can be beefed up.

Also I am exploring the possibility of putting a 6.2 diesel in it, that is a different issue at the moment, but it is heavier than a SBC and needs heavier springs as well.

Thanks!!!