Provides plenty of vac. And it's certified by Uncle Sam to be free from any bad manners. However, since the Federal government recognizes the SD-455 as part of the 455 engine family, the SD version doesn't have to run the durability tests, but can use a deterioration factor defined by a standard 455 four-barrel engine. Just when we had fast cars relegated to the museum sections, Pontiac has surprised everyone and opened a whole new exhibit. in. But if those are to be the rules of the game, they will still play . The 'X' is for the SD engine The idea of the registry is to publish each model year in viewable format. . They'd much rather think about winning in NASCAR or NHRA than merely chasing hydrocarbons.

That is a rare quality these days, especially in a car which has the one-dimensional appearance of a Super Car, but which less ostentatiously has incorporated the subtle improvements that have traditionally sold high performance sport cars. There should have been. Opposition came, was strong, pervasive, almost overwhelming; but Adams, McCully and Nell, in their naive dedication, have won out. The SD-455 passes the same emission tests after a 4000-mile break-in as does every other production engine. But the SD-455 is a whole new breed of car, not just an engine. but with their own entry.

Think of the Street Hemis, the L88s, the Boss 429s. Let your concentration wander over the truly fast cars of today, the 454 Corvettes, 911 Porsches, Panteras and Jaguar V-12s—but only briefly, because they are merely mid-14-second quarter-mile cars.

They were supported by a handful of emissions engineers who predicted that certification of a performance engine to 1973 standards would be impossible. On the seventh of February, 1973, our test Firebird Trans Am SD-455 swept through the quarter-mile at Orange County International Raceway in Irvine, California in an elapsed time of 13.751 seconds and at a terminal speed of 103.56 mph. But Pontiac has defied all that. Nineteen hundred and seventy-three, unobtrusively perhaps, is the year of the fastest Firebird ever. As a final reserve, there were the antediluvian members of management . 535 cu.in. . The outside of their Super Duty engine is cleverly disguised to look exactly like a standard Firebird 455 V-8. For extra insurance, the engine is assembled with generous clearances. In addition, enough material must be left over for sufficient wall thickness in case the casting cores shift—and they do in production. . The registry is a work in progress and will only be successful through participation from SD 455 enthusiasts. There was no cheering throng in the shut-off area, not a single pat on the hoodscoop for the over-achiever 1973 Trans Am. Among Sporty Cars, only the AMC Javelin and the Firebird offer engines over 351 cu. The block is reinforced with thicker bulkheads, 4-bolt main bearings and more material in the camshaft and lifter area. The background music is Funkytown by Lipps Inc. Tom Nell, Gregg Peterson and Herb Adams, joined later by John Sawruk and others, took the then-current 455 engine and improved it, rather than developing something completely fresh. It is only that kinship to a volume engine that makes it a reality. Warranty: There is no warranty or guarantee on high performance street or race engines or parts. It's all summed up by the equation of the year in Detroit: EGR (Exhaust Gas Recirculation) to fight NOx (Nitrous Oxide), at the expense of bhp and mpg. And that power flows off the crankshaft in astounding quantities, an impressive total of 310 net horsepower. Relish it as you would a Cuban cigar.