1964 273 ci

Ok i do not know any casting numbers right off but, the 4v head, and intake on a 273 are different from a 2v. Heres why, on a 2v head, and intake the bolt head is a 9/16 size, however on a 273 4v its 1/2. U are probley going "well so what" but the whole setup between the 2 are differnet with the angle of the bolt as well.

65+ was the year of the hi-po. The hipo was a 273 4v. I have seen a number of these cars in a 273 2v and also 4v.
I have seen a 64 with a 4v but im not sure if it was real. "meaning someone put that top end in it"

There is a lot of mistery as to what the early 64 barracudas were offered, it is likey if they did do a hi-po car in 64, it would be a later year, fender tag may tell no lies, as someone will chime in and lay it down.