78 GMC K15 Cassette Radio?

Hi guys, does anyone know if the 78 GMC K15 or Chevy K10 came from the dealer with a GM/Delco radio with cassette player (possibly GM 2700)? I have the parts catalog and it lists 995992 for the AM/FM radio and 996742 for the AM/FM with cassette. However, there is an asterisk by the listing and all I can find with a cassette player is a GM2700. It looks similar, but for the money, I'd like to be sure it'll fit in the stock bezel opening. Any info would be greatly appreciated. Thanks.