A hotly contested discussion in the hobby is the color of the master cylinder. The unit on this particular Firebird was painted black; rust indicates its machined surfaces were left natural. The gold finish on the power-brake booster appears to be zinc dichromate or cadmium. Visible directly beneath it is the cast-iron combination valve, which was left natural during assembly, as evidenced by the rust. Identification tags on the master-cylinder clamp and brake booster should match the appropriate boxes on the buildsheet, telling workers which units this particular Firebird was to receive during assembly.
Where the four spark plug wires pass over the driver-side valve cover and No. 7 separates off and runs downward, the remaining three then pass through another clip. On this particular Firebird, the open hole is nearest to the carburetor, while on others it’s nearest the master cylinder. It was likely the installer’s choice!
Flat-black paint was applied over the red-oxide primer base on the firewall. Seam sealer was applied quickly and heavily, and the braided engine-ground strap’s contorted appearance also hints of a fast moving line. The black overspray on the windshield-wiper motor is from the dealer-installed undercoat package.
A paper tag on the coil cover of the HEI distributor is for easy identification and installation. Its last four digits (3269) are the same as those of the complete part number, 1003269. The tach lead (single brown wire containing a fusible link) runs parallel to the firewall and approaches the distributor cap from the rear. Note how tightly the spark plug wires are routed in relation to the distributor cap. Spark plug wire loom clips are used to keep them separated to prevent cross arcing.
“E” stamped in black on the alternator case is likely some sort of inspection mark. We see that its fan, pulley, and the retaining nut are all plated in clear zinc and the lower spacer is left natural.
The wires exiting the main engine harness are grouped using a plastic tie, and from the appearance, it looks to have been performed hastily. The wires partially shield the valve-cover-identification tag, which denotes the engine-application code and base-spark-timing setting. Gathered with it is the Shaker drain tube, which happens to be broken off from the Shaker housing.
The hose connecting the air cleaner to the fresh air duct located in the fender is constructed of woven fiber. Usually missing on a well-used car, those that remain are often tattered beyond use. The yellow stamping on the radiator hose contains manufacturer information, as well as an identification code to ensure the correct unit is installed at the time of assembly. In addition to yellow, HPP has documented white stampings on other original cars.
Amazingly, the 400 in this Trans Am retains its original oil filter, which was installed prior to the engine being painted, as evidenced by the surface rust on the block and oil pan that the filter shielded from being completely covered. The black overspray present on the filter and oil-pressure-sending unit is the dealer-installed undercoat. The bolt protruding downward from the boss cast into the automatic transmission case serves no purpose! The hole is not even threaded and the bolt dangles loosely in it. Your guess is as good as ours on this one!
On this T/A, the hood latch is as clean as the day it left the factory. The body appears to be coated in black phosphate, while the latch mechanism is cadmium-plated. A close look at the fasteners that secure it and other pieces to the radiator support reveal that not only are they coated in black phosphate, the manufacturer markings are different, which indicates the assembly plant used various hardware suppliers and matching them was not a priority.
The emissions label contains detailed information about the engine, its spark advance and idle speed settings, and the emissions-control system. Each particular engine had its own label, which can be identified by the two-digit code located in the upper left-hand corner. Code-FA in this instance is for the 400-inch base mill backed by an automatic transmission. This particular label can be difficult to source today, as it isn’t frequently reproduced. Visible just beneath the label is the stamped part number for the radiator support (527654), as well as the day it was produced—February 28, 1977, which is typical for a vehicle built in mid-April. Join us next month as the exploration continues.