I'm pretty sure that if you measure the stubs the ends go on you will find they are 5/16, on my old mk1 sierra before I had a sapphy arb on the rear I made a link about 4" long each side with a rod end on each end, chopped the "bulge" part off the stub, drilled the centre of the stub and tapped to about 5mm, then used a washer/bolt to hold each end firm.
I then went sapphy type arb, in 16mm, the std 3 door arb on the rear is imo a waste of time and effort.
tabetha