K frame question

[1958300]

Are the K frames for the 1963-66 A body cars the same as the 1967-76 cars? I know they went to a different motor mount in 1973, but I'm trying to find out if they will interchange between the early and later models

 

[mopardude318]

they are totally different...

 

[Badart]

The early cars frame rails are about 2" narrower too.