The Camaro actually weighs right about what your old Chevy weighs. Bit lighter, but not really all that much. It would be what I recommend to use if you really want a highway driver with a good inline.
My Rat rod has a 1994 Ford Ranger front end on it. It's not perfect by any means, but it will do what I want it to. However, I wouldn't think of it for my 1951 Chevy..