GM A-Body Paint/Plating Information
All of the General Motors engine compartments are very similar. Each division may have made small changes to suit their individual applications, and each have their own engine colors, but the major components color of parts, and plating that are used remain essentially the same. I would emphasize that research is the key. When you take your engine out for rebuilding or detailing, photograph the components before they are disassembled. Remove the parts and note whether they are plated, painted, or just natural. When the car is being reassembled the parts should be returned to their original condition. Through research it's been discovered that the following components should be restored as shown. Naturally there are always exceptions for a given year but these can be used as a guideline.
Accelerator rod, accelerator lever:
Black oxide.
Alternator:
Natural aluminum finish, no paint or plating.
Alternator fan:
Zinc plated (silver).
Alternator pulley:
Silver cad plated or gold cad plated (depending upon the application).
Most plating shops can handle either application.
Battery box hold down clamp:
Semi-gloss black.
Brake distribution bracket:
Cadmium dichromate.
Brake lines:
Natural steel, no paint or plating.
Brake line clips:
We've seen these clips in natural finish, black oxide, and zinc chromate
(green) finish.
Clutch cross shaft:
Gray phosphate plate.
Clutch linkage parts:
Gloss black finish.
Clutch fork:
Natural steel finishes that can be painted with cast-iron spray paint.
Clutch return spring:
Natural steel or gray phosphate.
Clutch return spring bracket:
Natural steel finish.
Control arm cross shafts:
Semi-gloss black enamel.
Control arm bolts and large-end washers:
Natural steel.
Control arm adjustment shims:
Natural steel.
Engine accessory braided ground strap:
Natural, no paint or plating.
Engine dipstick handle:
Natural steel finish.
Exhaust manifolds:
This is another area where the GM divisions differed. According to restoration
sources, Chevrolet exhaust manifolds were over-sprayed when the engine
was painted. According to Pontiac sources, Pontiac engines were painted
first, then the exhaust manifolds was installed. Whatever the case may
be, if you are going to drive the car, any over- spray that may be sprayed
on the exhaust manifolds will bum off quickly.
Exhaust manifold locks:
The exhaust manifold locks were natural finish unless the exhaust manifolds
were painted; then they were over-sprayed.
Fan blades:
Fans on GM cars differed from brand to brand. Some divisions, like Chevrolet,
painted the fan and blades black, while other GM divisions used natural
stainless fan blades with black center hubs. If the fan was a clutch-type,
the clutch was natural aluminum with a gold cadmium center. The clutch
shaft and spring are natural finish.
Fender bolts, fender bolt washers:
Black oxide.
Frame or sub frame:
The frame and sub frame on all Sixties through Seventies GM muscle cars
were painted semi-gloss black. Some restorers like the frames a little
more on the shiny side, while others like a flatter finish. There are
a lot of different formulas for this and different paints you can use.
Most restorers use acrylic enamel or acrylic urethane finishes with
a flattening agent for frame components because of their durability,
One formula that you can use is as follows:
3 qt. PPG Delstar mixing black
1 qt. flattening agent
PPG DTR601 quick-dry reducer
Front springs:
Natural metal.
Fuel lines:
Natural steel finish, no paint or plating,
Heater/heater shroud:
Semi-gloss to gloss black lacquer. Generally, more shine than the engine
compartment.
Hood hinges, hood latch, hood catch, hood springs:
These components look like they are natural finish, but they were actually
gray phosphate plated. This process is available from several plating
companies. Upper and lower alternator brackets: Most pulleys and brackets
used on GM cars were painted semi-gloss black, but there are some
exceptions to the rule. Research your particular car because on some
GM brands, individual pulleys could have also been gray phosphates,
zinc, or cad plated. Some of the GM divisions also used large aluminum
brackets that were natural aluminum in color.
Horns:
Gloss black finish.
Horn relay:
Natural, no paint.
Ignition wire dividers:
Black plastic.
Inner fenders, firewall, radiator support:
As with the frame, there are many different formulas that can be used
to achieve a semi gloss black paint to match the factory finish. Some
restorers like to mix their own paint to get the shine they desire,
but. many restorers also use a premixed PPG paint for their engine compartment.
We have used PPG 9423 lacquer on our cars and it is about as close as
you can get to the factory finish, We usually buy it in quart cans because
that's enough to do a complete engine compartment. Many of the spray
can manufacturers (e.g. Krylon, VHT) make a semi-gloss black that also
looks good on engine compartment components if you don't have professional
spray painting equipment. If you have spray equipment here's another
custom lacquer formula that you can use:
2 qt. PPG mixing black #386
1 qt. universal flattening agent
1 qt. mixing clear #3 10
PPG DTL16 thinner
Master cylinder:
Most of the GM cars came with natural finish master cylinders. For a
lasting natural look, they can be painted with cast-iron gray paint,
which is available from a variety of sources such as The Eastwood Company,
VHT, and Krylon.
Master cylinder lid:
The master cylinder lid should be cadmium dichromate (gold
rainbow cad This type of plating is available from several sources.
The master cylinder bail clips are natural metal.
PCV- hose clips:
Black oxide.
Power brake booster:
All GM power brake boosters were cadmium dichromate. The two companies
mentioned above can rebuild and re-plate your power-booster.
Power brake hose clips:
Black oxide.
Power steering pump:
Gloss black enamel.
Power steering brackets:
Semi-gloss black enamel. Some brackets may actually look like a cross
between semi-gloss and gloss black.
Radiator:
All GM cars of this era had Harrison radiators that were painted gloss
black.
Radiator cap:
Radiator caps were not painted, they were plated.
Radiator shroud:
Radiator shrouds should be left natural plastic. Some shrouds on early
GM cars were steel and they should be painted semi-gloss to gloss black.
Shock absorbers:
Gloss gray enamel.
Steering box:
The cast-iron portion of the box is natural finish. The access lid is
natural aluminum; the bolts are black oxide.
Stabilizer bar:
Depending upon the GM division, these can be natural or semi-gloss black.
Stabilizer bar brackets:
Depending upon the GM division and supplier, the brackets can be semi-gloss
black or natural.
Tie rods, steering components:
Natural steel finish. These components can be painted with clear or
cast-iron colored paint.
Voltage regulator cover:
Gloss-black enamel.
Water pump pulley, crankshaft pulley:
Semi-gloss black, some crank pulleys were cast and left natural finish.
Some water pump pulleys on early GM muscle cars were zinc plated.
Windshield wiper motor:
Gloss black finish.
