How to set gcc 4.8 as default gcc compiler

I recently installed gcc 4.8 using brew on OSX 10.7.5 (Lion). I can now compile using gcc 4.8 by using g++-4.8 some_file.c or using the default gcc 4.2 by using g++ some_file.c I want to use gcc 4.8 as the default compiler for Xcode and if I type gcc at the terminal. I suppose I must alter gcc-related links within dirname $(which gcc). When I do ls -al $(dirname $(which gcc)) | grep 'gcc\|g++\|c++' I get the following: lrwxr-xr-x 1 root wheel 7 Jul 31 12:17 c++ -> clang++ -rwxr-xr-x 1 root wheel 909360 Nov 18 2011 c++filt lrwxr-xr-x 1 root wheel 5 Jul 31 12:17 clang++ -> clang lrwxr-xr-x 1 root wheel 12 Jul 31 12:17 g++ -> llvm-g++-4.2 lrwxr-xr-x 1 root wheel 12 Jul 31 12:17 gcc -> llvm-gcc-4.2 lrwxr-xr-x 1 root wheel 28 Jul 31 12:17 gcov-4.2 -> ../llvm-gcc-4.2/bin/gcov-4.2 lrwxr-xr-x 1 root wheel 52 Jul 31 12:17 i686-apple-darwin11-llvm-g++-4.2 -> ../llvm-gcc-4.2/bin/i686-apple-darwin11-llvm-g++-4.2 lrwxr-xr-x 1 root wheel 52 Jul 31 12:17 i686-apple-darwin11-llvm-gcc-4.2 -> ../llvm-gcc-4.2/bin/i686-apple-darwin11-llvm-gcc-4.2 lrwxr-xr-x 1 root wheel 32 Jul 31 12:17 llvm-cpp-4.2 -> ../llvm-gcc-4.2/bin/llvm-cpp-4.2 lrwxr-xr-x 1 root wheel 32 Jul 31 12:17 llvm-g++ -> ../llvm-gcc-4.2/bin/llvm-g++-4.2 lrwxr-xr-x 1 root wheel 32 Jul 31 12:17 llvm-g++-4.2 -> ../llvm-gcc-4.2/bin/llvm-g++-4.2 lrwxr-xr-x 1 root wheel 32 Jul 31 12:17 llvm-gcc -> ../llvm-gcc-4.2/bin/llvm-gcc-4.2 lrwxr-xr-x 1 root wheel 32 Jul 31 12:17 llvm-gcc-4.2 -> ../llvm-gcc-4.2/bin/llvm-gcc-4.2 When I run: which gcc-4.8 I get /usr/local/bin/gcc-4.8. Steps to get this done would be very helpful. Please and thank you.