[olredalert]

----Jay,,,Those appear to be OK Custom Headers sidepipe mufflers. Long out of business, OK was located here in Michigan and they made these under contract to GM and merchandised them as well thru speed shops. I bought many sets back in the day. Similar to Hookers but different, if you know what I mean. The stuff sold to and then by GM had part numbers on the main pieces (headers and pipes). I have actually seen those #s stamped in. I have no idea, however, if the mufflers had any part number on them.
----These mufflers as well as the headers they went into were never installed by the factory on any new Corvette. They were sold over-the-counter. I know they were available in 1969 and probably earlier from GM as my 69 L88 had the factory pieces installed by the original owner in 1969 shortly after the car was delivered.
----Hope this helps.........Bill S