[gambit-list] 64 bit gambit

What is the appropriate way of compiling gambit on a 64 bit system? I'm working with gcc 4.0.1 on mac ox 10.5.4 (intel). I tried adding

CFLAGS="-m64"

to ./configure's command line options which almost worked until the build system attempted to actually create the gsi and gsc. It forgot the -m64 options at that point but manually executing the command with -m64 worked fine. After that though, gsc does not seem to compile scheme files with the the -m64 option which prevents them from being loadable unless i explicitely pass gsc

-cc-options "-m64"

Is there a way to make gsc remember this or perhaps am I going about the entire thing incorrectly?