Kirk Evans (Amerisport) makes a flat firewall kit. It relocates the alternator to the A/C bracket and runs off the spare A/C compressor pulley groove (assuming you or a prior owner have tossed the old York piston compressor in favor of a modern rotary) as depicted in the link JFB posted.
Other have had success relocating it farther rearward in it's original location, aided by modifying the mounting or switching to a Chevy style alternator that has a smaller shorter mount.
Kirk's kit includes a new steel firewall cover and can be had with varying degrees of finish on the upholstered bulkhead cover. Again different takes on this where owners have carefully removed the hump from the fiberglass bulkhead cover and modified it themselves.
Here's another view of Kirk's kit to show the bulkhead cover;http://pantera.infopop.cc/eve/...260003925#3260003925