I am pretty new at installing programs from source and want to make sure I am not
about to screw up my system.

I needed a fortran compiler to compile R on my home machine running Mandrake 9.1, so
I downloaded gcc-3.4.3 and untarred/zipped it

The install manual says
¨ First, we highly recommend that GCC be built into a separate directory than the sources which does not reside within the source tree. This is how we generally build GCC; building where srcdir == objdir should still work, but doesn't get extensive testing; building where objdir is a subdirectory of srcdir is unsupported."

so I did (roughly)
cd ~/src
mkdir gcc-3.4.3-obj
cd gcc-3.4.3-obj
../gcc-3.4.3/configure

I did not specify a --prefix, so the toplevel installation directory defaults to /usr/local.

I then did
make bootstrap

and left the machine overnight(!). In the morning I had a clean compile. I don't have dejagnu installed on the home machine so I decided to skip testing and move on to the final install. This is where I am worried.

The manual states
"Now that GCC has been built (and optionally tested), you can install it with

cd objdir; make install

We strongly recommend to install into a target directory where there is no previous version of GCC present. "

I still have gcc-3.3.? present under /usr/local. Will I be violating this strong recommendation if I just do make install? Should I have specified a different prefix at the configure stage? If so, is there a standard name?

Is there anything else I should do to keep the two versions of gcc from stepping on each other and to clean up after the install?

Sorry to pose such naive questions, but I would like reassurance.

thank you