All of the CWSX 2XXX cars had a transverse leaf spring in the front which the replicas don't have. I think Kirkham made some but am not sure. When he went to the CSX 3XXX series which was the 427 style, they used coil springs, the body was a little longer and I think it was wider by about 2/4". There are other changes that the people who are really knowledgeable can tell you about. Side pipes, & etc.
Ron
