I could not find shackle pins for my 1931 pickup so I started looking around and found wristpins out of a tractor at our engine overhaul machine shop that were thrown in the metal barrol that were 3/4 inch in diameter and the same length of the shackle pins.
I put them in me lathe and ground the end to the same taper of the shackle pins. THEY WORKED PERFECT plus they are thicker in the wall thickness. This saved me over $180.00 that new ones would have cost.