Featured Car of the Week: 1978 Pontiac Trans Am W72 Coupe Solar Gold

Gold w/Camel interior, 400/220hp W72 4-spd manual transmission, WS6 handling Pkg.

The word “Iconic” can be used to describe a choice few American muscle cars. And The Pontiac Trans Am is certainly one of them! It was introduced in ’69 as a limited edition to the Firebird line-up. And by the time the 3rd generation came out in ’76, the cars popularity and “Legendary” status has been firmly cemented in the consciousness of almost every car-loving teenage boy in the U.S.! And a little film called “Smokey and the Bandit” only heightened the car’s appeal by leaps and bounds! That film featured a Special Edition Black T/A w/Gold striping, and Black interior. However, there was another Special “Gold” Edition Trans Am that was only available in ’78. The package consisted of Solar Gold exterior with Camel interior, Gold cast aluminum “Snowflake” wheels, special striping, emblems, hood decal and Gold removable roof panels. You could get it in either a 4-spd manual or automatic, but what really made this ‘bird special was checking W72 and WS6 on your dealer order form. First, some technical stuff about the W72 . . .

Starting in 1978, Pontiac improved on the durability of the 6.6 liter engine by reviving the 481988 block casting, which was beefier than the 500557 used elsewhere. Research shows that all 6.6 liter (400 cid) blocks used for the 1978-1979 T/A 6.6 engines (W72) were cast through November 1977. It appears that the 1978 481988 XX blocks did not have material removed from the web area like the base 500557 400 blocks.

The T/A 6.6 engine shared many major internal engine parts with the base 6.6 Liter engine including pistons, connecting rods and crankshaft. Even though both 400 engines used the same aluminum alloy pistons, the T/A 6.6 engines used molly filled compression piston rings. In addition, the T/A 6.6 engines also used SAE 1016 locked in rod (press-in) piston pins.

Both 400 engines used standard cast Arma Steel connecting rods with Moraine 400 steel backed main bearings. A standard nodular cast iron crankshaft with Moraine 400 steel backed main bearings was used in both 400 engines. All T/A 6.6 engines used a harmonic balancer (P/N 477682) as a vibration damper instead of the rubber floated weight used on the base L78 400 engines.

The W72 engine used different heads than the base 6.6 Liter Pontiac motor. The head code for each of these applications is “6X-4” (P/N 500795). The smaller chambered 350-cid 6×4 heads measured between 91cc and 93cc. The base 6.6 liter used the larger combustion chamber 6×8 heads (P/N 500798) that measured between 98cc and 101cc. The smaller chambered 6×4 heads helped boost the compression ratio from 7.6:1 to an advertised 8:1.

The W72 6X-4 heads can be identified conclusively by the small #4 machined on the bottom of a small ridge that protrudes from the head. It’s located between the front and center exhaust ports directly above the spark plugs, in front of the temperature sensor. You’ll probably have to scrape off the paint, as the “4” is stamped into the face of the machined pad. While you’re at it, take a look at the valve covers; all W72 motors originally came with chrome valve covers.

Also introduced in ’78, the WS6 Handling Pkg was an upgrade to the suspension on the Trans Am (Named the “Trans Am Special Performance Package”) and on the Formulas and Trans Am’s in 1979 and later (Named the “Special Performance Package”). The package consisted of a larger diameter sway bar, tighter steering box gear ratio, GR70-15 raised white letter Goodyear Polysteel Radials, and also the 15×8 inch snowflake rims which the total package was between $251 and $324 upgrade cost depending if you also went with the W72 Performance Package as well. One of the main additions with the WS6 Performance Package was the 15×8 Snowflake rims which really gave the car a wider stance.

Starting with the Gold Special Ed. Pkg and adding in the T/A 6.6 liter W72 engine and adding in the WS6 Performance Suspension Pkg. The very original and absolutely beautiful example presented here offers the best of what was available in a T/A back in ’78! Other options include, factory A-C, Custom Trim Group, tinted glass all around, am/fm stereo, tilt steering wheel and controlled cycle windshield wipers. The car is also equipped with 17″ T/A style Snowflake wheels wrapped in performance rubber. Stk #5864

For more info and photos:  http://corvettemike.com/used-corvettes-for-sale/1978-Pontiac-Trans-Am-W72-2440