in reply to net::ssh2 module wont install RHEL6

In addition to the previous comment, try listing the contents of these packages (rpm -ql <packagename>, if I remember it properly). The -dev packages have files (*.h) in /usr/include/, so other programs can be built and linked against the libraries (which are *.so in /usr/lib/) from the non-development packages.
Sorry if my advice was wrong.