But it was the Super Duty 455 option that was over the top. Adams was developing 303 Pontiac engines for SCCA racing and 366 engines for NASCAR. Management asked why he and his team were working on racing engines when Pontiac wasn't involved in racing, and then suggested they apply what they had learned to create something potent for the street. So team engineers Tom Nell and Jeff Young went right to work on what would become the Super Duty 455.
Pontiac engineers took the biggest-cubed engine available and added everything they could within the limitations of mass production. What the Chrysler Hemi was to Mopar, the Super Duty 455 would be to Pontiac—a stout engine that could be easily converted to racing. The team started with a four-bolt main block (the standard 455 had a two-bolt main block) with reinforced bulkheads and beefier camshaft and lifter bosses. Due to GM's low-compression mandate, 8.25:1-compression forged pistons and rods were used. The crankshaft was cast-iron, but nitride heat-treated and with greater oil clearances. An 80-psi oil pump and a baffled oil pan kept everything lubed, and the block was set up with a plug for a racing dry-sump oil system. These guys were very serious.
The heads had a similar design as the '69 Ram Air IV units, with big, round exhaust ports, and larger intake valves with 45-degree seat angles instead of the regular 30 degrees. The cast-iron exhaust manifolds were designed like headers and were only for the Super Duty 455. The camshaft profile used the same duration as Ram Air IV—308/320 degrees, but with 0.470-inch lift for the intake and exhaust. Rocker ratio remained at 1.5:1
The published rating of 310 hp at 4,000 rpm was somewhat misleading. Remember, these were the early days of net power ratings, and the engine could easily rev to 6,000 rpm. That much power from an engine with only 8.25:1 compression is mighty impressive. The objective of the Super Duty 455 was to provide a strong foundation upon which buyers could build Firebird racecars. Running high 13s in the quarter-mile out of the box, the Super Duty 455 could have easily run with the 454 Chevys and Hemi Mopars of '70.
But performance has never been cheap. The Super Duty 455 option listed for $675. (In comparison, an LS4 454 Corvette engine was only $250.) To take the edge off a little, the Super Duty 455 could be ordered on the less expensive Formula Firebird. The Formula Firebird cost $3,276 and the Trans-Am cost $4,204. Buyers who wanted a Trans Am, the Super Duty 455, and few other goodies were looking at $5,000. While the Formula didn't have the bling of the Trans Am, the car used the same Y99 handling package as the Trans Am, and all the standard Firebird options were available.
Not everyone was thrilled with the Super Duty 455. Management aside, the biggest obstacle was the assembly plant. Adams said there was very little cooperation in the engine plant—their attitude was “ho-hum.”
The car magazines did a great job of stoking the enthusiasts, and in short order, there were approximately 600 orders for the Super Duty 455. The plan was to have enough parts to build at least 1,000 engines, but mysteriously 400 sets of Super Duty 455 parts were pilfered! Yes, stolen! Or possibly disposed of. Remember, these were the days of bad blood between labor and management. Consequentially, dealers were charging as much as a $1,000 premium on the engine. For the company, the Super Duty 455 was somewhat of a headache, as it was a low-volume option and didn't make much money for all the trouble. A total of 295 were built in '73, and 1,001 in '74. That was it.
While the '73 Super Duty 455 option didn't save the Firebird, per se, '73 was a pivotal year for the Firebird. The screaming chicken hood-decal option provided Pontiac with a signature graphic for its new flagship performance car. Designers and engineers proved passion for performance can save a car line.