![]() They are available from most restoration parts supply houses specializing in Pontiacs for a reasonable cost. They continue to be a popular choice for many high-performance builds where a stock appearance is desired. Claims that molten aluminum would literally drip from the exhaust system may be a bit exaggerated, but I have seen the dividing wall between the center ports eroded away.Īt least two companies offer near-exact reproductions of Pontiac’s most famous exhaust manifolds. Durability issues were common in vehicles that were operated for extended periods. The cast-aluminum header was significantly lighter and performed suitably, but aluminum alloy technology and the casting and heat-treating processes were in their infancy. A cast-aluminum version was developed to reduce overall vehicle weight for those regularly competing in drag races. Available through dealership parts departments, Pontiac’s high-flow cast headers became part of its factory-installed Super Duty package introduced in 1962. Basically a cast header constructed of iron, it featured a bolt-on collector that had a separate flange that could be uncapped to bypass the remaining exhaust system to achieve maximum performance in competition settings. A Super Long Branch version is available with a 3-inch collector.Ī low-restriction, dual-exhaust system to allow greatest possible performance was made available in 1956 and commonly used through 1974, at which point a single exhaust catalyst was added, ending the possibility of using true dual exhausts.Īs engine displacement increased throughout the 1950s and 1960s, Pontiac began experimenting with high-flow exhaust manifolds that featured long, individual runners that merged into a large collector area to improve horsepower, particularly at high RPM. RARE offers excellent reproductions with 2.5-inch collectors. The “long branch” manifold fits many full-size Pontiac models from the 1960s including the Grand Prix, as well as first-generation Firebirds. An abbreviated version of the cast Super Duty header was developed for Pontiac’s high-performance street applications.
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