The pins can be reused a number of times if you don't destroy them. It's a good idea to have a set on hand. Some of the cheaper generic pads don't come with shims, but if you insist on having them, like to try and eliminate squeal, they can be purchased separately. Personally, I discard them if they come with the pads because sometimes it's too much work pressing the pistons all the way back in the calipers. That's always been the hardest and most time-consuming part of brake jobs on these cars for me.

Here's a tip: Don't throw away the thickest ones of the old brake pads because you can use them to replace completely worn-out ones while waiting for new pads to arrive. You can even swap the inside and outside ones because they wear unevenly. The first time my back brakes wore out (one pad down to the backing plate) I had to fabricate an new pad from an old Chev pad I had in the garage. Sometimes it helps to be a packrat.
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1992 745 approaching 500k km