Shift rod rattle at rear coupler

I have a shift rod rattle that comes from the rear coupler area by the tranny. The shift rod bushing under the shifter has just been replaced and is in good condition. I have always had this problem and I think it is because I cannot locate the proper spring pin for the gearshift rod. According to my parts diagram there is a spring pin (311-711-235), cap (311-711-239), and screw (311-711-243), and a washer that holds it all together. I have only had an aftermarket pin that did not fit correctly and I also tried a bolt and nut, but both of these have slop and so there is a slight rattle that is transferred through the shift rod in the tunnel.

Can someone point me in the right direction where I can get these parts?

Thanks for the help.