If they are stainless they are not OE. Standard dual exhaust [N10] '69s built through May 17, 1969 had one-piece aluminized steel tailpipes configured as you described. As of May 19 they were revised to a "bright metal" finish which is basically chrome. However the tailpipes differed in design. The RH pipe was 2-pc construction with the tip nickel/chrome plated and welded to the rear half. It was then welded to the muffler. The LH pipe was unchanged, just polished and flash-chromed. It was clamped to the muffler. Several OE exhaust '69s built May through September still exist in this configuration. Chevy serviced chromed tailpipes well into the '80s but both were the 2-pc design. Not known if the 2 pc LH pipe was ever used in production. NC8 chambered exhaust used aluminized tailpipes only.
67-68 used short tailpipes that exited behind the rear wheels.