I replaced my side rails with unpolished stainless from Mar-K. They have welding instructions on their website but I elected to bolt mine on so that I could be sure the bed sides would not rust around the welds. I sprayed on bedliner before bolting them on. I used one half inch long, quarter inch, stainless button head screws to hold them on. I put them about every six inches but spaced the ones at the front and rear so that no bolt heads show on the outside of the bed. The screws take a square or Phillips driver. Some might not like the look but it works for me since there's so many other bolt heads showing in the bed, and I wasn't going for show since I do actually haul stuff in it occasionally. I painted my bed wood black as original on these trucks. The nuts and lock washers take about three eights of an inch so you do loose that much tire clearance between tire and bed side.
