I think that is a real SS, at least the cowl tag is. A regular Impala could not be ordered with buckets and the A51 is for buckets, as stated. (Edit, I am wrong, A51 is for the "Sports Option" on a 66 Canadian Impala, which turns it into a Super Sport with all the SS badging, buckets and a console)
I'm not sure about the US cars but in Canada, a 163 is a 6 cylinder Impala, a 164 is a V8 Impala, a 166 is a Caprice. We never had a 167 or 168 in Canada in 1966.
Your Vin is 6 for 1966, 164 for V8 Impala, 37 for 2 dr ht, 0 for Oshawa plant, 05420 is the sequence number.
Last edited by Darth; 09-22-2014 at 12:14 AM.