One of the issues I see is with the amount of arch, the c10's have 2" more arch than the 3600 does. Secondly, you're going to have to use the c10 spring mounts and hangers.

I don't know the frame width on the c10, but I'm willing to be it's not a bolt in, which means welding new spring perches onto the axle.

Another issue with the c10 springs is that they may run into rear running board mount, because they are longer than the originals.

Geesh, I'm sounding like a Debbie downer!!! LOL

Try looking at some Ford Ranger or Chevy Colorado springs.

http://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=1508

http://www.sdtrucksprings.com/index.php?main_page=product_info&products_id=7713

1954 3600 Chevy Truck
"The Fake Truck"
In the Stovebolt Gallery
More pix on Photobucket