[CentOS] CentOS 6 gcc is a bit old

gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-11) is a bit old.
There have been major changes since then.
I'd like a newer version.

If I have to, I expect that I can install from source.
I'd rather not.

Is there a CentOS 6-compatible repository
from which I can get a newer version?
Does a standard CentOS 7 repository have a newer version?
Does a CentOS 7-compatible repository have a newer version?

It's my understanding that to compile from source,
I will need to keep the gcc I have.
Otherwise I would have nothing to compile the source.
I expect that providing the right options will let old and new co-exist.
Is ensuring that I get the right gcc when I type "gcc"
just a matter of having the right search path for gcc?
Will I need to do anything interesting to ensure that
the resulting executables run using the right libraries?

I've installed from source before,
but never to replace an existing compiler.
My concern is that if I louse things up,
the mess could be very hard to fix.

-- 
Michael   hennebry at web.cs.ndsu.NoDak.edu
"SCSI is NOT magic. There are *fundamental technical
reasons* why it is necessary to sacrifice a young
goat to your SCSI chain now and then."   --   John Woods