Jim is right. For most new stereo stuff, it is best to be on the safe side and wire it seperately. I reccomend running a 8 guage wire into the passenger compartment and mount an accesory fuse block. This allows you to wire up all kinds of aftermarket accesories(guages, etc.) without overloading the factory harness. Plus, it makes them all removable at a later time. Save a lot of hassle and makes thing real clean.
67 Pro-touring Camaro-327, 9:1, Comp XE268 Cam, Perf. RPM Intake. 750 Holley, Sportsman II Heads, Ceramic coated headers, 700R4 trans, 17" Amer. Racing TT2's, 12" disc brakes, custom stereo, black with white stripes, cowl ind. hood.