[SS427]

Joe,
To all intents and purposes in '67 and '68 the answer would be yes. Technically in '69 the answer should be yes as well. The difference being, in a standard Impala or Caprice, the 335hp 427 was the normal option but you could upgrade to the 390 hp. The big difference is the Impala SS was ONLY available as an SS427 in 1969. Literature states that the SS427 Impala was only available in 1969 with the 390 hp version but I have documents showing to the contrary as they could be had with the 335 hp 427.