Walker exhaust number

Back in the late 80's I bought from my local NAPA a set of 69 Dart 340 tailpipes. Was going to use them on my wife's 70 Dart as NAPA did not have a listing for dual pipes for the 70 Dart. Their listing (which was from a catalog so pre-computerized) showed only for the 69 Dart. FWIW, those pipes are still up in my rafters!