When you shop for a big-block engine, you expect the superior power capabilities and raw output that can transform your fledgling car project into a beast unfurled onto the open road. Pontiac 455 engines are great choices for those big block needs. The 455 engine dates back to the 1970s, having a 4.150-inch bore and 4.210-inch stroke. Starting in 1970, these engines come available in most full-size Pontiac models, including the Grand Prix and GTO, but there are also Buick 455 engines, as well. With such a long stroke relative to bore, these engines have an emphasis on torque, but you may be hard-pressed to find official spec ratings for various models. Many times spec ratings were undervalued for insurance or commercial purposes. Although generally, you can assume they reach around 500 lbs. per foot of torque. The 1970 Grand Prix, for instance, is listed as reaching 370 horsepower with its 455 engine. There are also high-output and super-duty versions of the 455, abbreviated as HO and SD, respectively. However, these engines can be rare finds, so searching through the vast inventory on eBay is a smart place to start looking. The 455 SD, in particular, is considered one of the strongest racing engines of the era, with so much torque and refined internal design, these are the gems you want to search for if you want superior Pontiac performance.Shop the large inventory of motors, parts, accessories, and complete engines for Buick!