New front leaf springs for sale or trade

[Tully]

I got these front leafs with a truck I bought. I put one on my 71 K 20 and they would have lifted my front end about 4". I don't know what other years they will fit, but they would fit on my 72 K 20 if I used narrower bushings. I don't know what brand they are but they measure 42 1/2" center of hole to hole, and 2 1/2" wide.
I don't know what they are worth so you guys can shoot me some offers or I would trade for a good black steering wheel (69 to 72) with a black GMC horn button or four GMC hub caps. The caps I want are from a newer truck (I think) with a red GMC on the rears and a 4" center hole in the fronts. These are for 16" rims and measure 11 5/8" inside the back side.(see pics)