1970 GMC Poly Leaf Spring Bushings
 

Does anyone know of a manufacturer or part number for polyurethane leaf spring bushings for a 1970 GMC C2500 w/HD springs? The current bushing inner sleeve is about 2.75" long. The OD on the steel outer sleeve is just under 1.25". the leaves, themselves, are about 2.25" wide. I think that I can find rubber, but I would really prefer poly. I have checked with the usual suspects (Energy Suspension etc.) If they have it, they don't know that they do.