Migrating to clang from GCC

Hi All,
          I am not sure whether its the right forum to ask this question. I am trying to move to clang compiler from GCC, but our software has tons of components independently developed provding different static archive libraries. All these libraries are finally linked into executable. Now rather than compiling every component with clang from scratch, I was thinking to pick one component at time to compile with clang and use GCC compiled static archives for other components to link into executable using clang compiler. Would this always work ?

So my question is whether GCC compiled object/archives involving C/C++ code would always be compatible with clang generated object files and can be mixed together during link step using clang compiler. Would this always work if I can make sure that our libraries are not using any features of C++11 .

Regards
Ankit