Don't know about the '73, but early B body cars it is a slant 6 or V8 K option.
Thanks,
Gary H.
> -------Original Message-------
>
> I'm sure someone will correct me if I'm wrong(lol), but I always thought
> that there were two different K-frames? One for small block engines and one
> for big block. And to put a big block in a small built car you needed
> special motor mounts?
>
>
> DJ