old54truckluvr
ESPO Springs & Things used to have the best prices. Their on-line catalog is not much help but give them a call: 1-800-903-9019
If you are a stickler for authentic appearance, check
Eaton Detroit Springs . They can provide leaf springs with original-style leaf-clips or band/rubber leaf-clips.
For comparison,
Chevy Duty sells the rear leaf springs for $210 (each) plus shipping.
It looks like 1947.5-1955.5 1/2 ton Chevrolet trucks had the same rear leaf-springs.
Tim