I saved this a while back. I know it is a little more info than you actually for and it does not include your original answer but I see people have already helped...
Underhood Detailing:
Frame and upper/lower control arms and upper shafts = semi-gloss black Front coil springs = gloss black or natural (better detail contrast) Firewall, inner fenders, radiator support = semi-gloss black Radiator and fan = gloss black Fan clutch = natural aluminum Radiator shroud = natural black plastic or gloss black Steering box = natural cast iron gray Steering linkage = natural steel Front sway bar = natural cast iron gray Heater or AC housing = semigloss black Hood hinges, latch, catch and springs = gray phosphate plated Brackets and steel pulleys = semi-gloss or gloss black (gloss gives more detail contrast) Cast iron pulleys = natural cast iron Master cylinder = natural cast iron (some use gloss black) Brake booster = gold cadmium plated (master cylinder lid also) Windshield wiper motor = gloss black Alternator = natural aluminum Power steering pump = gloss black AC compressor = semi-gloss black Steering column shaft = natural steel Horns = gloss black Coil = gloss black Voltage regulator = gloss black Distributor = natural aluminum with gloss black cap Fuel and brake lines = natural steel Undercarriage Details: Transmission = natural aluminum Bellhousing = natural aluminum Transmission support = semi-gloss black Driveshaft = natural steel Rear axle = semi-gloss black Rear swaybar = semi-gloss black
Rear coil springs = gloss black Rear control arms = semi-gloss black Gas tank = natural steel (shiny) Gas tank straps = gloss black
Parking brake cables = natural steel