Pontiac 455 Super Duty V8 with 505 hp and 500 ft-lbs of torque. This engine features the following parts:
- Cast Crank
- GM Rods
- ARP Rod Bolts
- Pontiac 455 block-bored-decked-honed
- Speed-pro 300`-.500" lift cam (CS-199R)
As with all our remanufactured engines, this Pontiac 455 Super Duty V8 features new pistons, rings, complete gasket set, oil pump, and valvetrain installed. The block is bored and honed and new cam bearings and freeze plugs are installed. The heads are resurfaced, featuring new guides and seals, then refinished with a 3-angle valve job. Crankshafts are reground and micro polished to factory specs. Each motor is pretested for compression, oil pressure, and oil flow before leaving the factory.
Our 12 month limited warranty covers parts for 12 months unlimited mileage.
History of the Pontiac 455 V8 (Ram Air V)
In 1969 Pontiac created several versions of their "tunnel port" engine: a special short-deck version of the V8 for Trans Am racing and a 400 standard deck version. The factory also experimented with 366 and 455 in?? versions. The cylinder head was patterned after the highly successful Ford 427 tunnel port head. So large were the intake ports that the pushrods ran through the center of the ports via pressed-in tubes.
For 1970, the 428 bore was expaned to a 4.152 inches, combined with a 4.21 inch stroke (105.5 mm by 106.9 mm), yielding a total displacement of 455 in?? (7.5 L). The engine became available for the first time in Pontiac Firebirds and the Pontiac GTO, as GM lifted its restrictions on the use of big-block engines in mid-sized cars. The Pontiac V8 design differs from other manufacturer's designs in that the external dimensions of each engine, from 326 - 455 in?? displacement, is identical. The displacement is determined internally with changes to the bore and stroke; therefore, there is no "big block" Pontiac engine. The 455 was used through 1976.
The 455, with its "undersquare" dimensions (long stroke relative to bore), emphasized torque over hp, and was somewhat less powerful than some high-performance iterations of the 400. For 1971 Pontiac introduced a High Output, H.O., version with stronger internal parts and improved cylinder head design for better breathing, making some 335 hp/224 kW (310 hp in the more accurate SAE net system), but this was an extremely rare engine. In 1973, a further refined and even stronger version, the Super Duty (SD) engine was introduced with "only" 310 hp/231 kW (SAE net) using a similar camshaft specifications to the Ram Air IV 400 and similar round port cylinder heads with specific "LS2" intake and cast iron exhaust header-manifolds. Still, it was the strongest American engine offered that year. Its power was achieved through bending of EPA emissions-testing procedures, which led engineers to de-tune the engine to 290 hp (216 kW) via a camshaft change for mid 1973 and 1974, after which point it was discontinued.
While an evolution of the RAIV and H.O. engine designs, the 455 SD was a much improved engine. In addition to thicker casting of the block, refined cylinder heads, reinforcements in the lifter galley and improvements to the crankshaft and connecting rods, the SD was made with a provision for dry sump oiling from the factory. This truly was a racing engine, detuned for use in passenger cars.