1981 to 1977 C10 front clip swap

[mik555]

I currently have a 1981 C10, well the front clip is a 1981. It is registered as a 1977 C10. Not sure if it was 1977 and they changed the front end after an accident or if its a 1981 and someone was able to reregister it as a 1977. Either way I have always understood that the parts are interchangeable. Is this true? Can I swap out the radiator support, fenders, grill, hood, inner wheel wells and all the other pieces? I know where someone is parting out a 1976 that I can pull from but I don't want to waste the money if it won't fit.
Thanks