Use specific local gcc and related libraries with Homebrew
No, it's not possible. When you install gcc, you must satisfied the required dependencies, otherwise this packages will be installed to ensure that works property.

Required: gmp ✔, libmpc ✘, mpfr ✘, cloog ✘, isl ✘


Same occurs on linux system, you can install gcc without it's dependencies:

Depends: cpp-4.8 (= 4.8.2-19ubuntu1), gcc-4.8-base (= 4.8.2-19ubuntu1), binutils (&gt;= 2.24), libgcc-4.8-dev (= 4.8.2-19ubuntu1), libc6 (&gt;= 2.14), libcloog-isl4 (&gt;= 0.17), libgmp10, libisl10 (&gt;= 0.10), libmpc3, libmpfr4 (&gt;= 3.1.2), zlib1g (&gt;= 1:1.1.4)
Recommends: libc6-dev (&gt;= 2.13-0ubuntu6)